08-06-2007 06:15 AM - edited 03-05-2019 05:44 PM
Hi all,
Recently implemented a new 2801 802.1q trunk to a 2950 switch, every 3 seconds we get a burst of around 1,000 input errors on the 2801 router, but nothing shown on the interface on the switch.
We've replaced:
2801 router
Cables between the two (twice)
swapped the ports on the 2950 switch (swapping out isn't really a simple option at present)
Can anyone suggest why we might be seeing this as it seems a very standard setup, and one that we have in many other sites without problems.
2801 config:
interface FastEthernet0/1
description Switch LAN
no ip address
speed 100
full-duplex
!
interface FastEthernet0/1.1
encapsulation dot1Q 1 native
ip address 10.10.10.1 255.255.255.248
no snmp trap link-status
on the 2950:
interface FastEthernet0/1
description **UPLINK**
switchport trunk allowed vlan 1,123,126,140,142,152
switchport mode trunk
speed 100
duplex full
!
Help!!
08-06-2007 06:43 AM
Silly me, it helps if I show you the output of sh int fe0/1 on the 2801 router:
FastEthernet0/1 is up, line protocol is up
Hardware is Gt96k FE, address is 001b.d4a8.e9ef (bia 001b.d4a8.e9ef)
Description: Switch LAN
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 2/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 494000 bits/sec, 201 packets/sec
5 minute output rate 1037000 bits/sec, 194 packets/sec
3319239 packets input, 1095006885 bytes
Received 395281 broadcasts, 0 runts, 0 giants, 0 throttles
2990410 input errors, 1525 CRC, 0 frame, 1 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
3247271 packets output, 2459860913 bytes, 0 underruns
0 output errors, 0 collisions, 4 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
And on the 2950 switch:
FastEthernet0/2 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 0013.7f66.2a42 (bia 0013.7f66.2a42)
Description: **UPLINK**
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 2/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is 100BaseTX
input flow-control is unsupported output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:00, output hang never
Last clearing of "show interface" counters 23w5d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1176000 bits/sec, 214 packets/sec
5 minute output rate 544000 bits/sec, 216 packets/sec
31641533 packets input, 3327594976 bytes, 0 no buffer
Received 2236903 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
12 input errors, 8 CRC, 4 frame, 0 overrun, 0 ignored
0 watchdog, 218798 multicast, 0 pause input
0 input packets with dribble condition detected
133611358 packets output, 1567316521 bytes, 0 underruns
0 output errors, 368 collisions, 2 interface resets
0 babbles, 0 late collision, 1691 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
08-06-2007 09:55 AM
On your switch port interfaces, apply the
"switchport trunk encapsulation dot1q"
Hope this help.
08-06-2007 11:38 PM
Thanks for the advice, however this is a new 2950 switch, with new IOS (12.1(22)EA2) which uses dot1q as native, so doesn't need or accept this statement.
Encapsulation is definately working, as the switch/trunks are operating perfectly, just the errors.
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