HP 6125XLG User manual

HP 6125XLG Blade Switch
TRILL
Configuration Guide
Part number: 5998-5383a
Software version: Release 240x
Document version: 6W101-20150515

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i
Contents
Configuring TRILL·························································································································································· 1
Overview············································································································································································1
Basic concepts ··························································································································································1
TRILL frame formats···················································································································································1
How TRILL works·······················································································································································3
TRILL forwarding mechanisms ·································································································································3
Protocols and standards ··········································································································································5
Configuration restrictions and guidelines·······················································································································5
TRILL configuration task list···············································································································································6
Enabling TRILL····································································································································································6
Configuration restrictions and guidelines ··············································································································6
Configuration procedure ·········································································································································7
Configuring the system ID and nickname for an RB······································································································8
Configuring the link type of a TRILL port·························································································································8
Configuring the DRB priority of a TRILL port···················································································································9
Setting the link cost for a TRILL port·································································································································9
Configuring the announcing VLANs and designated VLAN ····················································································· 10
Configuring TRILL timers ················································································································································ 10
Adjusting LSP parameters·············································································································································· 11
Adjusting the SPF algorithm parameters······················································································································ 13
Configuring the TRILL unicast equal-cost routes··········································································································· 13
Configuring TRILL distribution trees ······························································································································ 13
Enabling logging of TRILL neighbor changes·············································································································· 14
Configuring SNMP for TRILL·········································································································································· 15
Configuring TRILL GR ····················································································································································· 15
Displaying and maintaining TRILL································································································································· 16
TRILL configuration example·········································································································································· 17
Network requirements··········································································································································· 17
Configuration procedure ······································································································································ 17
Verifying the configuration··································································································································· 19
Support and other resources ·····································································································································21
Contacting HP ································································································································································ 21
Subscription service ·············································································································································· 21
Related information························································································································································ 21
Documents······························································································································································ 21
Websites································································································································································· 21
Conventions ···································································································································································· 22
Index ···········································································································································································24

1
Configuring TRILL
Transparent Interconnect of Lots of Links (TRILL) uses IS-IS to provide transparent Layer 2 forwarding.
Overview
TRILL combines the simplicity and flexibility of Layer 2 switching with the stability, scalability, and rapid
convergence capability of Layer 3 routing. All these advantages make TRILL very suitable for large flat
Layer 2 networks in data centers.
Basic concepts
•RBridge—Routing bridge (RB) that runs TRILL. RBs are classified into ingress RBs, transit RBs, and
egress RBs, depending on their positions in the TRILL network. A frame enters the TRILL network
through an ingress RB, travels along transit RBs, and leaves the TRILL network through an egress RB,
as shown in Figure 2.
•TRILL network—A Layer 2 network comprised of RBs, as shown in Figure 3.
•System ID—Unique identifier of an RB in the TRILL network. The system ID is 6-byte.
•Nickname—Address of an RB in the TRILL network. The nickname is 2-byte.
•Link State Database—The LSDB contains all link state information in the TRILL network.
•Link State Protocol Data Unit—An LSP describes local link state information and is advertised
between neighbor devices.
•Designated Routing Bridge (DRB)—Similar to the designated IS (DIS) in IS-IS, a DRB exists in the
broadcast network. It helps simplify network topology, and appoints AVFs and appointed ports for
the VLANs on each RB in the broadcast network.
•Appointed VLAN-x Forwarder (AVF) and appointed port—To avoid loops, TRILL requires all the
traffic of a VLAN on a broadcast network to enter and leave the TRILL network through the same
port of an RB. The RB is the AVF of the VLAN, and the port is the appointed port.
For more information about LSDB, LSPDU, and DIS, see Layer 3—IP Routing Configuration Guide.
TRILL frame formats
TRILL frames include control frames and data frames.
TRILL control frames include TRILL Hello, LSP, CSNP, PSNP, MTU-probe, and MTU-ack. These control
frames use 802.1Q encapsulation, and have a fixed destination multicast address 0180-C200-0041.
TRILL data frames have a specific format, as shown in Figure 1. A TRILL header and an outer Ethernet
header are added to the original Ethernet frame.

2
Figure 1 TRILL data frame format
Table 1 describes the fields in the TRILL header.
Table 1 TRILL header fields
Field Descri
p
tion
Ethertype The Ethertype is fixed to TRILL.
V Version number, which is 0. When an RB receives a TRILL frame, it checks the V
field and drops the frame if the Vfield is not 0.
R Reserved for future extension. An ingress RB sets the R field to 0when adding a
TRILL header. Transit RBs and egress RBs ignore the field.
M
Multi-destination attribute:
•0—Known unicast frame.
•1—Multicast, broadcast, or unknown unicast frame.
Op-Length Length of the Options field. 0indicates that the Options field does not exist.
Hop Count Hop count, which is used to avoid loops. An RB drops a TRILL frame whose hop
count is decremented to 0.
Egress RB Nickname Nickname of the egress RB.
Ingress RB Nickname Nickname of the ingress RB.
Options Options field. This field exists when the Op-Length field is non-zero.

3
How TRILL works
TRILL establishes and maintains adjacencies between RBs by periodically advertising Hello frames,
distributes LSPs among RB neighbors, and generates an LSDB for all RBs in the network. Based on the
LSDB, each RB uses the SPF algorithm to calculate forwarding entries destined to other RBs.
TRILL forwarding mechanisms
Different types of frames are forwarded using different forwarding mechanisms. The following sections
describe these mechanisms.
Unicast frame forwarding mechanism
As shown in Figure 2, a unicast frame is forwarded as follows:
1. When a unicast frame enters the TRILL network, the ingress RB encapsulates the original Ethernet
frame with a TRILL header (like an IP header) and an outer Ethernet header (like the Ethernet header
of a regular Ethernet frame).
2. RBs forward the frame hop by hop according to the egress RB nickname in the TRILL header to the
egress RB in the same way routers forward IP packets. Each hop replaces the outer Ethernet header
with an appropriate outer Ethernet header, and decrements the hop count in the TRILL header.
3. Upon receiving the TRILL frame, the egress RB de-encapsulates it to obtain the original Ethernet
frame, and sends the frame to the target device.
Figure 2 Unicast frame forwarding flow
The outer Ethernet header enables traditional Ethernet switches to forward TRILL frames and connect RBs.
Multi-destination frame forwarding mechanism
In a TRILL network, RBs do the following:
VLAN 10 VLAN 200 VLAN 300 VLAN 10
Ingress RB
RB 1
S1 S2
Ethernet frame TRILL frame TRILL frame Ethernet frame
Egress RB
RB 3
Transit RB
RB 2
Ingress RB = RB 1
Outer VLAN = 200
Egress RB = RB 3
Outer S-MAC = RB 1
Outer D-MAC = RB 2
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = S2
Ingress RB = RB 1
Outer VLAN = 300
Egress RB = RB 3
Outer S-MAC = RB 2
Outer D-MAC = RB 3
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = S2
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = S2
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = S2
Unicast frame

4
•Compute a TRILL distribution tree for each VLAN according to the LSDB.
•Use the TRILL distribution tree to guide the forwarding of multi-destination frames, which include
multicast, broadcast, and unknown unicast frames in the VLAN.
As shown in Figure 3,when a multicast frame from VLAN 10 enters the TRILL network, RB 1, which is an
ingress RB, encapsulates the multicast frame into a TRILL frame. In the frame, the egress RB is RB 2, the
root bridge of the TRILL distribution tree for VLAN 10. When the frame arrives at the root bridge, it is
distributed throughout the TRILL distribution tree. Then, the TRILL frame is decapsulated by RB 3 and sent
to the destination station S2. Because the network segment where RB 4 resides does not have a receiver
of this frame, RB 4 drops the frame.
Figure 3 Multicast frame forwarding flow
TRILL selects distribution trees for forwarding multicast, broadcast, and unknown unicast frames based on
the VLANs to which the frames belong. Because the topologies of TRILL distribution trees are different,
traffic can be load shared. However, equal-cost links are not used for load sharing.
When N equal-cost links exist in the network, each TRILL distribution tree selects the link with the largest
pseudonode ID for forwarding packets. As shown in Figure 4, two equal-cost links exist between RB 1
and RB 3. Assume the link directly connecting RB 1 to RB 3 has the largest pseudonode ID. Both the TRILL
distribution tree rooted at RB 3 and the TRILL distribution tree rooted at RB 4 select the link. For more
information about pseudonode IDs, see Layer 3—IP Routing Configuration Guide.
VLAN 10VLAN 10
S1 S2
VLAN 200
TRILL network
RB 1
Ethernet frame
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = Multi
TRILL frame
Ingress RB = RB 1
Outer VLAN = 200
Egress RB = RB 2
Outer S-MAC = RB 1
Outer D-MAC = All RBs
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = Multi
TRILL frame
Ingress RB = RB 1
Outer VLAN = 200
Egress RB = RB 2
Outer S-MAC = RB 2
Outer D-MAC = All RBs
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = Multi
RB 4
RB 3
Ethernet frame
Payload
Inner VLAN = 10
Inner S-MAC = S1
Inner D-MAC = Multi
RB 2
Multicast frame Distribution tree
of VLAN 10
Root bridge of
distribution tree
Leaf of
distribution tree

5
Figure 4 Multicast ECMP
TRILL distribution trees support Equal Cost Multiple Path (ECMP), also known as multicast ECMP. When
multicast ECMP is enabled, TRILL assigns equal-cost links to different TRILL distributions trees. This
improves the load sharing performance.
When N equal-cost links exist in the network, each TRILL distribution tree selects an equal-cost link for
forwarding packets through J mod N in root bridge priority order. J is the priority sequence number of a
TRILL distribution tree and starts from 0.
As shown in Figure 4:
•The link directly connecting RB 1 to RB 3 is assigned to the TRILL distribution tree rooted at RB 3.
•The link RB 1-RB 2-RB 3 is assigned to the TRILL distribution tree rooted at RB 4.
TRILL distribution trees support fast switching the roots. When an RB finds that the root of a distribution
tree is unreachable based on the unicast route calculation, the RB actively ages out the LSPs of the root
in the LSDB, and triggers the TRILL network to recalculate the multicast route information. This feature
makes sure multicast, broadcast, and unknown unicast traffic can be fast switched to the newly calculated
distribution tree.
Protocols and standards
•RFC 6325, Routing Bridges (RBridges): Base Protocol Specification
•RFC 6326, Transparent Interconnection of Lots of Links (TRILL) Use of IS-IS
•RFC 6327, Routing Bridges (RBridges): Adjacency
•RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
Configuration restrictions and guidelines
When you configure TRILL, follow these restrictions and guidelines:
•Configuration in Layer 2 Ethernet interface view takes effect on only the current port. Configuration
in Layer 2 aggregate interface view takes effect on the current interface and its member ports.
Configuration on the member port of an aggregate interface takes effect after the member port
leaves the aggregation group.
•To connect a common Layer 2 network to a TRILL network, enable the spanning tree protocol on the
common Layer 2 network and disable the spanning tree protocol on the TRILL network. For more
information about spanning tree protocols, see Layer 2—LAN Switching Configuration Guide.
RB 1 RB 2
RB 3
RB 4
Cost=3
Cost = 1

6
•HP recommends not enabling loop detection on TRILL ports, because TRILL networks prevent loops
from being generated. For more information about loopback detection, see Layer 2—LAN
Switching Configuration Guide.
•Do not configure the TPID for VLAN tags on RBs. For more information about TPIDs, see Layer 2
— LAN Switching Configuration Guide.
•Do not connect multiple TRILL ports on an RB to the same link. Otherwise, these TRILL ports might be
elected as the AVFs of a VLAN at the same time because these TRILL ports cannot sense each other.
This will cause loops in the VLAN.
TRILL configuration task list
Tasks at a
g
lance
(Required.) Enabling TRILL
(Required.) Configuring the system ID and nickname for an RB
(Optional.) Configuring the link type of a TRILL port
(Optional.) Configuring the DRB priority of a TRILL port
(Optional.) Setting the link cost for a TRILL port
(Optional.) Configuring the announcing VLANs and designated VLAN
(Optional.) Configuring TRILL timers
(Optional.) Adjusting LSP parameters
(Optional.) Adjusting the SPF algorithm parameters
(Optional.) Configuring the TRILL unicast equal-cost routes
(Optional.) Configuring TRILL distribution trees
(Optional.) Enabling logging of TRILL neighbor changes
(Optional.) Configuring SNMP for TRILL
(Optional.) Configuring TRILL GR
Enabling TRILL
After you enable TRILL on a port, TRILL can operate correctly by using default settings. A port with TRILL
enabled is called a "TRILL port."
Configuration restrictions and guidelines
When you enable TRILL, follow these guidelines:
•To enable TRILL on a port, first enable TRILL globally.
•Enable or disable TRILL on all ports in a VLAN, so that the ports in a VLAN have the same TRILL
status (enabled or disabled).
•Do not enable both TRILL and EVB on a port. The allowed VLAN list of a TRILL-enabled port cannot
overlap with that of an EVB-enabled port. For more information about EVB, see EVB Configuration
Guide.

7
•When you set up a TRILL network, avoid the case that multiple TRILL neighbors are established for
one RB port. When you plan a network, avoid the networks shown in Figure 5 and Figure 6.
{Figure 5 shows a typical network where two TRILL neighbors are established for the same port
of an RB.
{In Figure 6, because TRILL is not enabled on the port connecting RB 2 to RB 3, the port will
transparently transmit the TRILL Hello frames from RB 3. As a result, two TRILL neighbors are
established for the port connecting RB 1 to RB 2.
Figure 5 Two TRILL neighbors are established for a port (1)
Figure 6 Two TRILL neighbors are established for a port (2)
Configuration procedure
To enable TRILL:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable TRILL globally
and enter TRILL view. trill By default, TRILL is disabled globally.
3. Return to system view. quit N/A
4. Enter Layer 2 Ethernet
or aggregate interface
view.
interface interface-type
interface-number N/A
5. Enable TRILL on the
port. trill enable By default, TRILL is disabled on a port.
Traditional Ethernet
switch
RB 1
RB 2 RB 3
TRILL enabled port

8
Configuring the system ID and nickname for an RB
The system ID and nickname of an RB are identifiers of the RB in the TRILL network.
•System ID—Unique identifier of an RB in the TRILL network. The system ID can be automatically
assigned or manually configured.
•Nickname—Address of an RB in the TRILL network. The address can be automatically assigned or
manually configured. When multiple RBs in the TRILL network have the same nickname, the RB with
the highest priority uses the nickname. When RBs have the same priority, the RB with the highest
system ID uses the nickname. The system automatically assigns new nicknames to the other RBs.
If you set a new different system ID for an RB, the system resets the TRILL process.
To configure the system ID and nickname for an RB:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Configure the system
ID for the RB. system-id system-id
By default, an RB automatically generates a
system ID according to its MAC address
upon startup.
4. Configure the
nickname for the RB.
nickname nickname [ priority
priority ]
By default, the system automatically assigns
nicknames to RBs, and the priority for a RB
to hold a nickname is 64.
Configuring the link type of a TRILL port
The following link types are available for a TRILL port:
•Access—Access ports include access ports without the alone attribute and access ports with the
alone attribute. Access ports with the alone attribute do not send or receive Hello frames and do not
participate in the DRB election or AVF negotiation. Access ports without the alone attribute can
process only local data frames and Hello frames.
•Hybrid—A hybrid port combines the attributes of an access port and a trunk port, and can process
local data frames and passing data frames.
•Trunk—A trunk port can process passing data frames and some of Layer 2 protocol frames (for
example, LLDP frames), but it cannot process local data frames.
To configure the link type of a TRILL port:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet
or aggregate
interface view.
interface interface-type
interface-number N/A
3. Configure the link
type of a TRILL port.
trill link-type { access [ alone ] |
hybrid |trunk }
By default, the link type of a TRILL port is
access without the alone attribute.

9
Configuring the DRB priority of a TRILL port
On a broadcast network, TRILL must elect a DRB. An RB with a higher DRB priority is preferred. When two
RBs have the same DRB priority, the RB with a higher MAC address takes precedence.
To configure the DRB priority of a TRILL port:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet or
aggregate interface
view.
interface interface-type
interface-number N/A
3. Configure the DRB
priority of a TRILL port. trill drb-priority priority By default, the DRB priority of a TRILL port is
64.
Setting the link cost for a TRILL port
The link cost of a TRILL port can be automatically calculated by the system or manually set:
•A manually set link cost takes precedence over a calculated link cost.
•If no link cost is set and automatic link cost calculation is enabled, the calculated link cost takes
effect.
•If no link cost is set and automatic link cost calculation is disabled, the default link cost 2000 is
used.
The system automatically calculates the link cost of a TRILL port by using the following formula: link cost
= 20000000000000/interface baud rate.
To set the link cost for a TRILL port:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Enable automatic link cost
calculation for TRILL ports. auto-cost enable
By default, automatic link cost
calculation is enabled for TRILL
ports.
4. Return to system view. quit N/A
5. Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
interface interface-type
interface-number N/A
6. Configure the link cost for a
TRILL port. trill cost value The default setting is 2000.

10
Configuring the announcing VLANs and
designated VLAN
The concepts and symbols used to describe a VLAN on a port are as follows:
•Enabled VLAN—A VLAN enabled on the port.
•Forwarding VLAN—A VLAN for which the port is the appointed port.
•∩and ∪—Set operation symbols. ∩indicates set-theoretic intersection, and ∪indicates
set-theoretic union.
RBs send Hello frames in a set of VLANs. The VLAN set is calculated as follows:
•DRB—Enabled VLANs ∩(announcing VLANs ∪designated VLAN).
•Non-DRB—Enabled VLANs ∩(designated VLAN ∪(announcing VLANs ∩forwarding VLANs)).
The designated VLAN forwards TRILL frames (except Hello frames) between RBs.
•If no designated VLAN is configured for the DRB of a link, the frames are exchanged through the
lowest-numbered enabled VLAN.
•If a designated VLAN is configured for the DRB of a link, the frames are exchanged through the
designated VLAN.
To configure the announcing VLANs and designated VLAN:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
interface interface-type
interface-number N/A
3. Configure announcing
VLANs. trill announcing-vlan { vlan-list | null }
By default, no announcing VLAN is
configured, and the announcing
VLANs are the enabled VLANs.
4. Configure the designated
VLAN. trill designated-vlan vlan-id By default, no designated VLAN is
configured.
Configuring TRILL timers
You can configure the following TRILL timers:
•Hello interval and Hello multiplier—An RB advertises Hello frames at the Hello interval to maintain
a TRILL adjacency. The shorter the Hello interval, the faster the network convergence. However, a
shorter Hello interval consumes more system resources. The adjacency holding time is obtained by
multiplying the Hello interval by the Hello multiplier. The RB advertises the adjacency holding time
to neighbors through Hello frames. If a neighbor does not receive any Hello frame from the RB
before the adjacency holding time expires, it removes the TRILL adjacency with the RB.
•Inhibition time—An RB that acts as the AVF of a VLAN guarantees that frames from the VLAN have
only one incoming port or one outgoing port along a link. When other RBs receive frames from the
VLAN, they do not perform any processing. However, when the RB detects that a root bridge
change occurs on a link or that the AVF advertised by other RBs conflicts with the local AVF, the RB

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inhibits the local AVF for a certain time to avoid loops. When the inhibition time expires, if the RB
is still the AVF of the VLAN, the RB restores the role of AVF.
•CSNP interval—On a broadcast network, the DRB advertises CSNPs at the CSNP interval to
perform network-wide LSDB synchronization. A CSNP records all LSP digests of the local LSDB.
When an RB receives a CSNP, the RB compares the CSNP against the local LSDB to verify whether
some LSPs are aged out or missing. If the CSNP has an LSP digest that the local LSDB does not have,
the RB sends a PSNP packet to request the LSP.
To configure TRILL timers:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet
or aggregate interface
view.
interface interface-type
interface-number N/A
3. Configure the Hello
interval. trill timer hello interval
The default setting is 10 seconds.
This command sets the Hello interval for the
RB. The Hello interval of the DRB is 1/3 of the
Hello interval of the RB, so that the DRB
failures can be quickly detected.
4. Configure the Hello
multiplier.
trill timer holding-multiplier
count The default setting is 3.
5. Configure the inhibition
time. trill timer avf-inhibited time The default setting is 30 seconds.
6. Configure the CSNP
interval. trill timer csnp interval The default setting is 10 seconds.
Adjusting LSP parameters
You can modify the following LSP parameters:
•LSP maximum age—An LSP originated by an RB uses the maximum age as the remaining lifetime.
When the remaining lifetime of an LSP in the LSDB is 0 seconds, the RB removes the LSP's content,
keeps the LSP's digest, and purges the LSP from the network by advertising the LSP that has the
remaining lifetime set to 0.
•LSP refresh interval—When the remaining lifetime of a locally originated LSP is no greater than
(maximum age – refresh interval), the LSP is refreshed even if no change occurs to it. This
mechanism avoids frequent LSP aging and ensures network stability.
•Maximum length of an LSP originated by an RB—The actual maximum LSP length is determined by
the smallest of following values:
{The configured value.
{The interface MTU.
{The maximum length of an LSP originated by an RB (which is carried in LSPs).
•Maximum length of an LSP that can be received by an RB—When the RB receives an LSP
exceeding the length, the RB drops the LSP.
•Overload bit of LSPs—When the Overload bit in the LSPs sent by an RB is set, the RB fails and
cannot correctly perform route selection and packet forwarding. When the RB cannot record the

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complete LSDB because of insufficient memory, routing calculation errors occur. To make
troubleshooting easier, temporarily exclude the RB from the TRILL network by setting the Overload
bit for the LSPs sent by the failed RB.
•Minimum LSP interval and maximum number of LSPs transmitted per time—To avoid frequent LSP
aging in the network, RBs periodically advertise LSPs. The actual refresh interval of an LSP is
determined by both the minimum LSP interval and the maximum number of LSPs transmitted per time.
To prevent LSPs from being aged out accidentally, set the LSP maximum age and the LSP refresh
interval appropriately.
To adjust LSP-related parameters:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Set the LSP maximum
age. timer lsp-max-age time The default setting is 1200 seconds.
4. Set the LSP refresh
interval. timer lsp-refresh time The default setting is 900 seconds.
5. Configure the
maximum length of an
LSP originated by an
RB.
lsp-length originate size
The default setting is 1458 bytes.
The maximum length of an LSP originated
by an RB cannot be greater than the
maximum length of an LSP that can be
received by an RB. Otherwise, the system
displays error messages.
6. Configure the
maximum length of an
LSP that can be
received by an RB.
lsp-length receive size
The default setting is 1492 bytes.
The maximum length of an LSP that can be
received by an RB cannot be smaller than
the maximum length of an LSP originated by
an RB. Otherwise, the system displays error
messages.
7. Set the Overload bit of
LSPs and set the lifetime
for the set Overload bit.
set-overload [ timeout ]
By default, the Overload bit is not set.
Do not set the Overload bit for LSPs sent by
the root bridge of a TRILL distribution tree.
Otherwise, the traffic to be forwarded
through the RB cannot be forwarded.
8. Return to system view. quit N/A
9. Enter Layer 2 Ethernet
or aggregate interface
view.
interface interface-type
interface-number N/A
10. Configure the minimum
LSP interval and the
maximum number of
LSPs transmitted per
time.
trill timer lsp interval [ count
count ]
By default, the minimum LSP interval is 10
milliseconds, and the maximum number of
LSPs transmitted per time is 5.

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Adjusting the SPF algorithm parameters
Based on the LSDB, an RB uses the SPF algorithm to calculate a shortest path tree with itself as the root.
The RB uses the shortest path tree to determine the next hop to a destination network. By adjusting the SFP
calculation intervals, you can prevent resource overconsumption when the network changes frequently.
When the network is stable, the SPF calculation interval for continuous calculations is reduced to
minimum-interval. When the network changes frequently, the SPF calculation interval is added by
incremental-interval × 2n-2 (where n is the times of continuous SPF calculations triggered) each time, but
the SPF calculation interval cannot exceed maximum-interval.
To adjust SPF algorithm parameters:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Set the SPF calculation
interval for TRILL.
timer spf maximum-interval
[ minimum-interval
[ incremental-interval ] ]
By default, the maximum SFP calculation
interval is 10 seconds, the minimum SPF
calculation interval is 10 milliseconds, and
the SFP calculation incremental interval is 20
milliseconds.
Configuring the TRILL unicast equal-cost routes
Configuring multiple equal-cost routes to the same destination implements load balancing among these
links and improves the link efficiency. You can configure the maximum number of TRILL unicast equal-cost
routes.
The maximum number of TRILL unicast equal-cost routes is restricted by the maximum number of
equal-cost routes. The maximum number of equal-cost routes can be configured by using the
max-ecmp-num command. It is in the range of 1 to 32. After you configure the maximum number of
equal-cost routes as n, the value range for the number argument of the max-unicast-load-balancing
command is 1 to n. For more information about the max-ecmp-num command, see Layer 3—IP Routing
Command Reference.
To configure the maximum number of TRILL unicast equal-cost routes:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Configure the maximum
number of TRILL unicast
equal-cost routes.
max-unicast-load-balancing
number The default setting is 8.
Configuring TRILL distribution trees
In a TRILL network, RBs do the following:

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•Compute TRILL distribution trees according to the LSDB.
•Use the TRILL distribution trees to guide the forwarding of multicast, broadcast, and unknown
unicast frames.
An RB with a higher priority is selected as the root bridge of a TRILL distribution tree.
An LSP carries TRILL distribution tree information that includes the following:
•The number of TRILL distribution trees that the RB wants all RBs to compute.
•The maximum number of TRILL distribution trees that the RB can compute (this number is fixed at 15).
•The number of TRILL distribution trees that the RB has computed.
An RB determines the number of TRILL distribution trees to compute (n) by selecting the lower value from
the following two values:
•The number of TRILL distribution trees that the highest-priority RB wants all RBs to compute.
•The smallest value of the maximum number of TRILL distribution trees that each RB can compute.
From the nickname list in the LSP advertised by the RB with the highest priority, the first nnicknames
comprise the root bridge list that the local RB uses to compute TRILL distribution trees.
When multicast ECMP is disabled, traffic can be load shared because the topologies of TRILL distribution
trees are different. However, equal-cost links are not used for load sharing. When multicast ECMP is
enabled, TRILL can assign equal-cost links to different TRILL distribution trees. This improves the load
sharing performance.
To configure the TRILL distribution trees:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Set a priority for the RB. tree-root priority priority The default setting is 32768.
4. Configure the number of
TRILL distribution trees that
the RB wants all RBs to
compute.
trees calculate count The default setting is 1.
5. Enable multicast ECMP. multicast-ecmp enable
By default, multicast ECMP is
disabled.
Make sure the multicast ECMP
status is the same on all RBs in the
TRILL network. Otherwise,
multicast, broadcast, and
unknown unicast frames might
fail to be forwarded.
Enabling logging of TRILL neighbor changes
Perform this task to output logs of TRILL neighbor changes to the configuration terminal.
To enable logging of TRILL neighbor changes:

15
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Enable logging of TRILL
neighbor changes. log-peer-change enable By default, logging of TRILL neighbor changes
is enabled.
Configuring SNMP for TRILL
After you enable SNMP notification sending for TRILL, TRILL will generate notifications to notify NMS of
important events on the local module and send the notifications to the SNMP module. You can set the
notification sending parameters in SNMP. For more information about notifications, see Network
Management and Monitoring Configuration Guide.
TRILL uses the IS-IS MIB to provide the TRILL object management function for NMS. Because the MIB
objects defined in the IS-IS MIB are single-instance management objects, NMS cannot manage IS-IS and
TRILL at the same time. According to the management for multiple OSPF instances defined in RFC 4750,
you can set a context name for the SNMP object for managing TRILL. In this way, the SNMP requests for
managing IS-IS and the SNMP requests for managing TRILL from NMS can be distinguished. Because the
context name is a concept specific to SNMPv3, the community names are mapped to context names for
distinguishing different protocols in SNMPv1/v2c.
To configure SNMP for TRILL:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable SNMP
notification sending
for TRILL.
snmp-agent trap enable trill
[ adjacency-state-change | area-mismatch |
buffsize-mismatch | id-length-mismatch |
lsdboverload-state-change | lsp-parse-error |
lsp-size-exceeded | max-seq-exceeded |
maxarea-mismatch | new-drb | own-lsp-purge
| protocol-support | rejected-adjacency |
skip-sequence-number | topology-change |
version-skew ] *
By default, SNMP
notification sending is
enabled for TRILL.
3. Enter TRILL view. trill N/A
4. Configure the context
name for the SNMP
object for managing
TRILL.
snmp context-name context-name
By default, no context name
is set for the SNMP object for
managing TRILL.
Configuring TRILL GR
Graceful Restart (GR) ensures the continuity of packet forwarding when a protocol restarts or an
active/standby switchover occurs. The device on which a protocol restarts or an active/standby
switchover occurs advertises the restart status to the neighbors, and allows the neighbors to re-establish
connections. GR involves the following roles:
•GR restarter—Graceful restarting router. It must be GR capable.

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•GR helper—A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
To configure TRILL GR:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Enable GR for TRILL. graceful-restart By default, GR is disabled for TRILL.
4. (Optional.) Configure
the GR interval for TRILL.
graceful-restart interval
interval The default setting is 300 seconds.
Displaying and maintaining TRILL
Execute the display commands in any view and the reset command in user view.
Task Command
Display TRILL ardency table
information.
display trill adjacent-table [ count | nickname nickname interface
interface-type interface-number ]
Display brief TRILL information. display trill brief
Display TRILL FIB information. display trill fib [ count | nickname nickname ]
Display TRILL GR status. display trill graceful-restart status
Display TRILL port information. display trill interface [ interface-type interface-number ]
Display TRILL LSDB information. display trill lsdb [ local | lsp-id lsp-id | verbose ] *
Display all ingress entries in the TRILL
multicast FIB (MFIB). display trill mfib ingress [ vlan vlan-id [ local-entry | remote-entry ] ]
Display all egress entries in the TRILL
MFIB.
display trill mfib transit [ nickname nickname [ prune-entry | rpf-entry
| vlan vlan-id [ mac-address mac-address ] ] ]
Display information about the TRILL
multicast routing table.
display trill multicast-route [ tree-root nickname [ vlan vlan-list [ mac
mac-address ] ] ]
Display the TRILL neighbor table. display trill neighbor-table
Display the TRILL neighbor statistics. display trill peer [ interface interface-type interface-number ]
Display the TRILL RPF check table
information. display trill rpf-table tree-root nickname
Display information about the TRILL
unicast routing table. display trill unicast-route [ nickname nickname ] [ verbose ]
Clear dynamic running statistics of
the TRILL process. reset trill

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TRILL configuration example
Network requirements
As shown in Figure 7, configure TRILL in the Layer 2 data center network as follows:
•Enable TRILL on the downlink ports of access layer devices to connect terminal devices to the TRILL
network.
•Enable TRILL on the uplink ports of access layer devices, and configure these uplink ports as trunk
ports to pass TRILL frames to the TRILL network.
•Enable TRILL on the downlink ports of distribution layer devices, and configure these downlink ports
as trunk ports to forward TRILL data frames.
•Enable TRILL on the uplink ports of the distribution layer devices. These ports send the decapsulated
TRILL data frames to the core layer.
•In the TRILL network, configure four TRILL distribution trees with RB 6 through RB 9 as the root bridges.
RB 6 through RB 9 are in descending priority order.
A hierarchical network has three layers (from up to down): the core layer, distribution layer, and access
layer. Usually, a port connecting to a higher layer device is called an uplink port, and a port connecting
to a lower layer device is called a downlink port.
Figure 7 Network diagram
Configuration procedure
This section provides only TRILL-related configurations.
This section assumes that the access layer devices are the HP 6125XLG blade switches and the
distribution layer devices are the HP 11900 switches.
1. Configure the downlink ports of access layer devices:
# Enable TRILL globally on RB 1, and enable TRILL on downlink port Ten-GigabitEthernet 1/0/1 of
RB 1.
Distribution layer
Access
layer
RB 6 RB 7 RB 8
RB 1 RB 2 RB 3 RB 4 RB 5
RB 9
Core layer
TRILL network