Cisco Router IOS XR Getting Started Manual page 65

Chapter 3 Bringing Up the Cisco IOS XR Software on a Multishelf System
Verifying Bidirectionality
To verify the bidirection for the integrated switch, you can use the Unidirectional Link Detection
(UDLD) protocol to detect unidirectional links on Ethernet ports. UDLD is a Layer 2 protocol. UDLD
is useful at linkup time. If the link is detected to be unidirectional, the port is shut down. In addition,
UDLD detects unidirectional failures after a port has been up and bidirectional for a certain time. If a
transceiver goes wrong, UDLD protects the control network from faulty transceivers that are plugged
into the control network.
To provide the port information that is disabled (UDLD), use the show controllers switch udld ports
command.
Verifying Unidirectional Link Detection (UDLD) Protocol Information
To verify Unidirectional Link Detection (UDLD) protocol information for intra-rack switches, use the
show controllers switch inter-rack udld location command, as shown in the following example:
RP/0/RP0/CPU0:router(admin)# show controllers switch inter-rack udld all location
f0/sc0/cpu0
Interface Gig port# 13
---
...
Current bidirectional state: Bidirectional
Current operational state: Advertisement - Single neighbor detected
...
...
Verifying Spanning Tree Protocol Information
To verify Spanning Tree Protocol (STP) information for intra-rack switches, use the show controllers
switch stp location command, as shown in the following example:
RP/0/RP0/CPU0:router(admin)# show controllers switch stp location f0/sc0/CPU0
##### MST
Bridge
Root
Regional Root address 5246.48f0.20ff
Operational
Configured
Interface
---------------- ---- --- --------- -------- ---------------------------
##### MST
Bridge
Root
OL-10957-02
Entry 1
---
...
Device name: 0_RP0_CPU0_Switch
Port ID: GE_Port_0
Neighbor echo 1 device: nodeF0_SC0_CPU0
Neighbor echo 1 port: Gig port# 13
0 vlans mapped:
address 0800.453e.469a
address 5246.48f0.20ff
port GE_Port_0
hello time 1, forward delay
hello time 1, forward delay
Role Sts Cost
1 vlans mapped:
address 0800.453e.469a
address 5246.48f0.20ff
port GE_Port_0
2-4094
priority 36864 (36864 sysid 0)
priority 32768 (32768 sysid 0)
path cost
priority 32768 (32768 sysid 0)
internal cost
6, max age
6, max age
Prio.Nbr Type
1
priority 36865 (36864 sysid 1)
priority 32769 (32768 sysid 1)
cost
Integrated Switch System
0
20000 rem hops 3
8, txholdcount 6
8, max hops 4
20000 rem hops 3
Cisco IOS XR Getting Started Guide
3-27