I've run into this situation while doing some practicing with the 3550s and some routers
2611------3550-------3550--------3640 all ethernet ports are set at full duplex 10 megabit speed. the 2611 and the 3640 are connected via a vlan tunnel. everything is working fine, until I turn on l2protocol-tunnel cdp on both switches, at which point I get the following error: 3640 FrameSwitch# 1w0d: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on Ethernet0/1 (not hal f duplex), with Router_14_2611 Ethernet0/1 (half duplex). 2611 1w0d: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on Ethernet0/1 (not ful l duplex), with FrameSwitch Ethernet0/1 (full duplex). as near as I can tell, there are no errors on any of the interfaces. no collisions, etc. not that I'm sending a lot of traffic during these studies, but extended pings don't come up with anything either. relevant configurations for all interfaces. as you can see, everything agrees all along the line. everyone is set for speed 10 and duplex full. if I turn off l2protocol-tuinnel cdp on the interfaces, the error messages disappear. I suspect a bug in CDP, but I'm wondering if I have missed anything. 2611 ------- interface Ethernet0/1 no ip address full-duplex ! interface Ethernet0/1.1 encapsulation dot1Q 121 ip address 122.1.1.1 255.255.255.0 ! interface Ethernet0/1.2 encapsulation dot1Q 122 ip address 122.1.2.1 255.255.255.0 ! interface Ethernet0/1.3 encapsulation dot1Q 123 ip address 122.1.3.1 255.255.255.0 ! interface Ethernet0/1.4 encapsulation dot1Q 124 ip address 122.1.4.1 255.255.255.0 ! Switch_24#sri f0/1 Building configuration... Current configuration : 200 bytes ! interface FastEthernet0/1 switchport access vlan 100 switchport mode dot1q-tunnel no ip address duplex full speed 10 l2protocol-tunnel cdp no cdp enable spanning-tree bpdufilter enable end interface FastEthernet0/26 switchport access vlan 100 switchport mode dot1q-tunnel no ip address duplex full speed 10 l2protocol-tunnel cdp no cdp enable spanning-tree bpdufilter enable end 3640 ------- interface Ethernet0/1 no ip address no ip redirects full-duplex priority-group 1 ! interface Ethernet0/1.1 encapsulation dot1Q 121 ip address 122.1.1.2 255.255.255.0 ! interface Ethernet0/1.2 encapsulation dot1Q 122 ip address 122.1.2.2 255.255.255.0 ! interface Ethernet0/1.3 encapsulation dot1Q 123 ip address 122.1.3.2 255.255.255.0 ! interface Ethernet0/1.4 encapsulation dot1Q 124 ip address 122.1.4.2 255.255.255.0 ! Chuck -- TANSTAAFL "there ain't no such thing as a free lunch" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=59929&t=59929 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
