02-01-2006 07:27 PM - edited 03-03-2019 01:39 AM
I'm connecting a 2811 router to a 2950 switch with an 802.1q trunk carrying 4 Vlans. All is well if the router is booted before the switch. However if the switch is booted first, proper connectivity doesn't happen. Pings between the two devices are sporadic. Also if the router is rebooted after the switch is up, pings between the two again become sporadic.
Any ideas - I'm at a loss to solve this one.
2811 is running IPVOICE - IOS 12.4 (5)
2950 is running IOS 12.1 (22)EA6
Router config on flaky link:
-------------------------------------
interface FastEthernet0/0
description Trunk to P3BRSW
no ip address
duplex full
speed 100
!
interface FastEthernet0/0.115
encapsulation dot1Q 115
ip address 10.3.115.1 255.255.255.0
ip helper-address 10.1.10.10
no snmp trap link-status
!
interface FastEthernet0/0.116
encapsulation dot1Q 116
ip address 10.3.116.1 255.255.255.0
ip helper-address 10.1.10.10
no snmp trap link-status
!
interface FastEthernet0/0.155
encapsulation dot1Q 155
ip address 10.3.155.1 255.255.255.0
ip helper-address 10.1.10.10
no snmp trap link-status
!
interface FastEthernet0/0.156
encapsulation dot1Q 156
ip address 10.3.156.1 255.255.255.0
ip helper-address 10.1.10.10
no snmp trap link-status
---------------
Cat 2950 config on flaky link:
interface FastEthernet0/24
description Trunk to P3BRR
switchport trunk allowed vlan 115,116,155,156
switchport mode trunk
switchport nonegotiate
speed 100
duplex full
spanning-tree portfast
end
The switch's management address is in Vlan 115
Any / all ideas very welcome.
Thanks
02-01-2006 08:02 PM
Hi,
Your interface config looks okay.. However, that may not be the issue.
When you say that you are getting sporadic pings, which 2 points are you pinging between ?
Paresh
02-01-2006 10:56 PM
Hello,
I wonder if turning off ´spanning-tree portfast´ on the 2950 trunk port makes a difference (´no spanning-tree portfast). Is the 2950 connected to another device ? If this is the only link between your devices, you might want to try and turn off spanning tree alltogether on the 2950 (no spanning-tree vlan x)...
Regards,
GP
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide