From: Shahnawaz Khot (shahnawaz4ccie@gmail.com)
Date: Sat Jul 12 2008 - 08:23:43 ART
Hi,
we have following question and setup in our IE practice labs.
SW3(port14,15) --> connected to --> SW1(port 17,18) then SW1(port
20,21) ---> connected to SW4(port 14,15)
Question is to configure layer 3 etherchannel between SW3 and SW4 on these
ports(port14,15) at either side. An additional vlan is allowed to create on
SW1 for dot1q tunneling.
We have configured SW3 and SW4 for layer3 etherchannel mode ON
configuration. we configured SW1(ports 17,18,20,21) for following interface
configuration.
switchport access vlan 100
switchport mode dot1q-tunnel
l2protocol-tunnel cdp
no cdp enable
spanning-tree bpdufilter enable
where addtional vlan 100 is used for all SW1 ports (17,18,20 and 21). This
works fine but the only issue is with cdp neighbour. Please refer the cdp
neighbour outputs on SW3 and SW4.
SW3#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
*SW4 Fas 0/15 174 R S I WS-C3550- Fas
0/15
SW4 Fas 0/14 174 R S I WS-C3550- Fas 0/15
SW4 Fas 0/15 174 R S I WS-C3550- Fas 0/14
SW4 Fas 0/14 174 R S I WS-C3550- Fas 0/14
*SW4 Fas 0/21 164 R S I WS-C3550- Fas
0/21
SW4 Fas 0/20 134 R S I WS-C3550- Fas 0/20
SW4 Fas 0/19 124 R S I WS-C3550- Fas 0/19
BB3 Fas 0/24 166 R 2610 Eth 0/0
SW1 Fas 0/13 121 R S I WS-C3560- Fas 0/16
SW2 Fas 0/18 150 R S I WS-C3560- Fas 0/18
SW2 Fas 0/17 150 R S I WS-C3560- Fas 0/17
SW2 Fas 0/16 150 R S I WS-C3560- Fas 0/16
*SW3 Fas 0/14 142 R S I WS-C3560- Fas
0/15
SW3 Fas 0/15 142 R S I WS-C3560- Fas 0/14
*R3 Fas 0/3 135 R S 3745 Fas 0/1
R5 Fas 0/5 144 R S I 2811 Fas 0/1
And SW4 has following output.
SW4#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability
Platform Port ID
R4.internetworkexpert.com
Fas 0/4 122 R S I 2811
Fas 0/1
*SW4 Fas 0/14 123 R S I
WS-C3550-2Fas 0/15
SW4 Fas 0/15 123 R S I
WS-C3550-2Fas 0/14
*SW1 Fas 0/13 130 R S I
WS-C3560-2Fas 0/19
*SW3 Fas 0/15 152 R S I
WS-C3560-2Fas 0/15
SW3 Fas 0/14 152 R S I
WS-C3560-2Fas 0/15
SW3 Fas 0/15 152 R S I
WS-C3560-2Fas 0/14
SW3 Fas 0/14 152 R S I
WS-C3560-2Fas 0/14
*SW3 Fas 0/21 130 R S I
WS-C3560-2Fas 0/21
SW3 Fas 0/20 143 R S I
WS-C3560-2Fas 0/20
SW3 Fas 0/19 143 R S I
WS-C3560-2Fas 0/19
R2 Fas 0/12 171 R S I 2811
Fas 0/1
R1 Fas 0/11 139 R S I 2811
Fas 0/1
R6 Fas 0/6 134 R S I 2811
Fas 0/1
On SW3 we are learning SW4 as neigbour twice on interfaces F0/14 and F0/15.
That means 4 times on these same interfaces. Also SW3 learns himself once on
each of these Fa0/14 and Fa0/15 interfaces. We found the similar
descripencies on SW4 also. But surprsingly we found no issues with
etherchannel operations. Please help us to understand this reason and please
let us know if we are missing something in our configuration to work CDP
correctly.
Thank you,
Best Regards.
Shahnawaz
This archive was generated by hypermail 2.1.4 : Mon Aug 04 2008 - 06:11:54 ART