I have a weird issue that I hope to explain clearly.
Toplogy:
Access----- Dist.---------- Core
3750X ------- 4500X ------- 6509
3750X - 3 switches in stack w/ redundant power supply and ring stack-power configured
4500X - 2 switches in VSS configuration
3750X have 2 uplinks to the Distribution
3570X - 4500X
g1/1/1 - t1/1/7 (uplink 1)
g2/1/1 - t2/1/7 (uplink 2)
Both interfaces are in a Port-Channel configuration.
IP's
3750X - 4500X - 6509
10.1.1.3 - 10.1.1.2 - 10.1.1.1
Problem:
3750X stopps passing traffic. Monitoring software alerts and notifies group of "down" condition.
Unable to traceroute or ping the 3750X
Troubleshooting Steps Taken:
1. Ping 3750X stack - no replies
2. Log into 4500X and ping 3750X - replies
3. SSH to 3750X from 4500X - able to login
4. Ping from 3750X to 4500X - replies
5. Ping from 3750X to 6509 - no replies
6. Checked CPU history - everything is normal
7. Checked temp. - everything normal
8. With constant ping from workstation to 3750X (10.1.1.3)
--Rebooted switch 1,
--after reboot constant ping had no change,
--Also lost ssh connection.
--ssh back into 3750X stack and was able to get back on, verified switch 1 was still rebooting
--No change in status after switch 1 reboot
9. With constat ping from worskstation to 3750X (10.1.1.3)
--Rebooted switch 1
--after reboot, ping started to reply.
This is the second time this has happen.
The first time I replaced switch 2, verified IOS, swapped stacking cables - so everything is new.
No crash files, no spanning tree issues (that I am aware of), no environmental issues, I have checked fiber and sfp's and found no issues.
For some reason the issue is resolved when we remove switch 2 from the stack every time, well reboot it.
Any ideas?
