Loss Of Two-Way Communication; Wrong Hello Interval On An Isl Interface - Cisco MDS 9000 Series Troubleshooting Manual

Chapter 4 Troubleshooting Switch Fabric Level Issues
S e n d c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m .

Loss of Two-way Communication

The following events occur when two-way communication is lost:
1.
2.
3.

Wrong Hello Interval on an ISL Interface

To identify a mismatch in the Hello interval on the two sides of an ISL interface, follow these steps:
To turn on debugging, enter the following command:
Step 1
switch1# debug fspf all
The system output looks like this:
switch1# debug fspf all
Jan
Jan
Step 2 To show FSPF information, enter the following command:
switch1# show fspf internal route v 1
The system output looks like this:
switch1# show fspf internal route v 1
FSPF Unicast Routes
---------------------------
VSAN Number
----------------------------------------------------------------------
1
1
1
1.
2.
Step 3 To view the currently configured FSPF parameters on the ISL, enter the following command:
switch1# show fspf v 1 interfac fc1/16
The system output looks like this:
switch1# show fspf v 1 interfac fc1/16
FSPF interface fc1/16 in VSAN 1
FSPF routing administrative state is active
Interface cost is 500
Timer intervals configured, Hello 5 s, Dead 80 s, Retransmit 5 s -----1
FSPF State is INIT -----2
Statistics counters :
Number of packets received : LSU
Number of packets transmitted : LSU
Number of times inactivity timer expired for the interface = 0
OL-5183-02, Cisco MDS SAN-OS Release 1.3
The Port enters Init state and removes its neighbor's domain ID from the Recipient Domain ID field
and inserts 0xFFFFFFFF.
FSPF Removes the ISL (inter switch link) from the topology database.
New LSRs (Link State Records) are flooded to adjacent switches to notify them that the FSPF
database has changed.
5 00:28:14 fspf: Wrong hello interval for packet on interface 100f000 in VSAN 1
5 00:28:14 fspf: Error in processing hello packet ,
Dest Domain
0xEF(239)
0xED(238)
0x01(1)
Indicates that there is no second path to Domain 238, through Domain 1 switch2.
Indicates that there is no direct path to Domain 1 switch2; traffic must travel through 3 ISLs.
Route Cost Next hops
1000
2000
3000
0 LSA 0 Hello 2
0 LSA 0 Hello 4
Cisco MDS 9000 Family Troubleshooting Guide
Troubleshooting FSPF Issues
error code = 4
fc1/1 -----1
fc1/1
fc1/1 -----2
Error packets 1
Retransmitted LSU 0
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