At work we switched from a Cisco Catalyst 3560G to a Catalyst 4500E a few weeks ago. Remember to issue the spanning-tree extend system-id command prior to enabling VTP version 3. During the test period, the Icinga instances logged packet losses of varying degree around the clock when doing ICMPv6 pings.

Read More → Lessons learned on Cisco Catalyst 4500E

I’ve noticed that Cisco VPN Client tends to fail with “Reason 414: Failed to establish a TCP connection.” on long-running Windows 7 SP1. It’s been going on for years.

Read More → Long-running Windows 7 SP1, Cisco VPN Client, and “Reason 414: Failed to establish a TCP connection”

While reloading a Cisco Catalyst 3560 running IOS 12.2(55)SE the other day, I noticed the switch stopped sending messages to the configured IPv6 enabled syslog host. Nothing appeared in the log files on the syslog host until I manually disabled and reenabled the log statement.

Read More → Logging messages from Cisco IOS 12.2(55)SE to an IPv6 enabled syslog host