Switch interfaces going up immediately after power-up

[mirekj]

What we see is that powering-up a redundant switch causes the whole network go crazy for over a minute.
We have a few switches (2950) connected to a few routers (2611) and the problem we are having is that when a switch is powered-up it brings its Ethernet interfaces up immediately (even before it boots). This causes the routers to see all the links change the state to up and start advertising the routes which are not available yet. Then, after ~30s the switch finishes booting and goes through spanning tree reconfiguration (another ~30) and eventually everything is OK again.
We have keepalives on the routers but they do not seem to be helping. Is there any way of putting some delay on the Ethernet interface (on either router or a switch)?

 

[apishko]

Something that you could try is don't connect the switch to the network. At first just connect to the switch via console connection. Power the switch up and manually shut down the interfaces. After the switch has been powered up connect it to the network and bring up the interfaces. Hope this helps.

 

[lui3]

what routing protocol are you using on the routers?


Lui3
CCNP,CCDA,A+/Net+
Cisco Wireless Specialization

 

[mirekj]

We are using EIGRP

 

[lui3]

use spanning-tree portfast on the switch interfaces connected to the routers. that will bring them up within 5 secs and they will stay up. no spanning tree. you should do this on all host ports as well.

Lui3
CCNP,CCDA,A+/Net+
Cisco Wireless Specialization