EtherChannel help!

Chris Knight

Trying to set up an etherchannel in a lab I have here at work.
Switch 2950 and 2900XL Both are running IOS v12.x
Here is a config on the 2950

[interface FastEthernet0/23
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
duplex full
speed 100
channel-group 1 mode desirable
channel-protocol pagp
end

Switch2#sh run int fa 0/24
Building configuration...

Current configuration : 181 bytes
!
interface FastEthernet0/24
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
duplex full
speed 100
channel-group 1 mode desirable
channel-protocol pagp
end]

on the 2900XL
[interface FastEthernet0/23
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
duplex full
speed 100
channel-group 1 mode desirable
channel-protocol pagp
end

Switch2#sh run int fa 0/24
Building configuration...

Current configuration : 181 bytes
!
interface FastEthernet0/24
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
duplex full
speed 100
channel-group 1 mode desirable
channel-protocol pagp
end]

Now I have both duplex, speed, dup vlans configured across the board. Now when I show etherchannel summary on the 2950 it shows this

[Switch2#sh etherchannel summary
Flags: D - down P - in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
u - unsuitable for bundling
U - in use f - failed to allocate aggregator
d - default port

Number of channel-groups in use: 1
Number of aggregators: 1

Group Port-channel Protocol Ports

---

+

---

+

---

+

---

1 Po1(SD) PAgP Fa0/23(I) Fa0/24(I) ]

Here is the output on the 2900xl
[om#sh ether
Com#sh etherchannel summary
Flags: d - default D - down
I - in use

Group Ports

---

---

1 Fa0/11(Id) Fa0/12(I)]

I thought it might be working but I guess not

Thoughts?[/code]

dtlokee

On the 2924xl can you specify the trunking encapsulation? If it's set to ISL (the default) and the 2950 only supports 802.1q trunking you will not form an etherchannel.

Deadmaster200

Yes, that's right. The 2900XL series supports both ISL and dot1q so you need to specify 8021q.

Chris Knight

Here is the config on the 2900xl series
[interface FastEthernet0/11
duplex full
speed 100
port group 1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
!
interface FastEthernet0/12
duplex full
speed 100
port group 1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,5,1002-1005
switchport mode trunk
!
interface VLAN1
ip address 10.10.10.3 255.255.255.0
no ip directed-broadcast
no ip route-cache]

The 2900xl is set for dot1q. The 2950 only supports dot1q so you wont see that in the config, as its by "default"

Any other suggestions?[/code]

dtlokee

Your second config for the 2900xl is different than the first one you posted, but here goes: the 2900xl does not support dynamic channel negotation so you need to set the 2950 to "channel-group 1 mode on" and that should fix the problem.

Chris Knight

Nice....
[Switch2#sh etherchannel summary
Flags: D - down P - in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
u - unsuitable for bundling
U - in use f - failed to allocate aggregator
d - default port

Number of channel-groups in use: 1
Number of aggregators: 1

Group Port-channel Protocol Ports

---

+

---

+

---

+

---

1 Po1(SU) - Fa0/23(P) Fa0/24(Pd) ]

Looking good I wish I had two 2950 switches.. I hate having an older switch and a new one.


Thanks again dtlokee [/code]