Re: [nsp] dot1q/isl "encapsulation failed"

From: Andrew (arousch@home.com)
Date: Thu Mar 08 2001 - 23:45:27 EST


encap failed is layer3's way of telling you that there is something wrong
in a layer below it. Where is 10.1.1.6?

At 11:20 PM 3/8/01 +0200, Dmitri Kalintsev wrote:
>Hi guys,
>
>I'm having rather hard time finding what's wrong in seemingly stupid
>situation:
>
>!
>interface FastEthernet0/0
> ip address <real ip address> 255.255.255.128
> no ip directed-broadcast
> full-duplex
>!
>interface FastEthernet0/0.1
> no ip redirects
> no ip directed-broadcast
>!
>interface FastEthernet0/0.77
> encapsulation dot1Q 77
> ip address 10.1.1.5 255.255.255.252
> no ip directed-broadcast
>!
>
>(I've tried no ip address on maininterface and f0/0.1 in dit1q vlan 1,
>result is the same).
>
>7206-vpn-test#ping 10.1.1.6
>
>Type escape sequence to abort.
>Sending 5, 100-byte ICMP Echos to 10.1.1.6, timeout is 2 seconds:
>
>19:41:37: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>sending
>19:41:37: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>encapsulation failed.
>19:41:39: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>sending
>19:41:39: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>encapsulation failed.
>19:41:41: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>sending
>19:41:41: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>encapsulation failed.
>19:41:43: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>sending
>19:41:43: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>encapsulation failed.
>19:41:45: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>sending
>19:41:45: IP: s=10.1.1.5 (local), d=10.1.1.6 (FastEthernet0/0.77), len 100,
>encapsulation failed.
>Success rate is 0 percent (0/5)
>
>I've tried to change dot1q to ISL, and result is the same, "encapsulation
>failed". FE works fine, if I don't use VLAN's. I've tried different IOS
>sets, too. Oh, yes. And a different router. First was 7206vxr with npe300
>and dual FE IO controller, this current one is 7206 with npe200 and vanilla
>IO controller. No difference.
>
>Switch side I presume is not guilty, as this very same switch runs a few
>dot1 trunks to other switches without problem. Switch is Cat2948, so it only
>supports dot1q trunks. Switch and router perfectly see each other on cdp
>neighbor list, too.
>
>7206-vpn-test#sh int f0/0.77
>FastEthernet0/0.77 is up, line protocol is up
> Hardware is DEC21140A, address is 0004.de2f.8000 (bia 0004.de2f.8000)
> Internet address is 10.1.1.5/30
> MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
> reliability 255/255, txload 1/255, rxload 1/255
> Encapsulation 802.1Q Virtual LAN, Vlan ID 77.
> ARP type: ARPA, ARP Timeout 04:00:00
>
>It seem to recognize that it's a VLAN interface, too...
>
>There is nothing really I can think of now, and what the hell should I think
>of? This is a simple configuration, as simple as it gets, and I had it
>working in dozens of other places. :( Any ideas?
>
>SY,
>--
>D.K.



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