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zombiecrab
Beginner

ethernet0 keeps bouncing

Hi,

I have just started messing around with cisco routers and I have run into a few things I can not found answers for.

Firstly:

I can configure a router and save the config with 'copy running-config startup-config' but when I restart the router the config is blank.

second:

sometimes I cant start a interface, in this case ethernet0. I issue the command and the interface just bounces.

wouter#show ip interface brief
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet1              unassigned      YES unset  administratively down down
FastEthernet2              unassigned      YES unset  administratively down down
FastEthernet3              unassigned      YES unset  administratively down down
FastEthernet4              unassigned      YES unset  administratively down down
Ethernet0                  81.137.49.110   YES manual down                  down
ATM0                       unassigned      YES manual administratively down down
Ethernet2                  unassigned      YES manual administratively down down

wouter#config terminal
Enter configuration commands, one per line.  End with CNTL/Z.
wouter(config)#interface ethernet0
wouter(config-if)#no shutdown
wouter(config-if)#shutdown
wouter(config-if)#
*Jan 10 04:47:32.559: %LINK-5-CHANGED: Interface Ethernet0, changed state to administratively down
wouter(config-if)#no shutdown
wouter(config-if)#
*Jan 10 04:47:48.639: %LINK-3-UPDOWN: Interface Ethernet0, changed state to up
*Jan 10 04:47:49.639: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up
*Jan 10 04:47:54.359: %LINK-3-UPDOWN: Interface Ethernet0, changed state to down
*Jan 10 04:47:55.359: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to down
wouter(config-if)#

No idea why this is happening and I can't find any info online.

The router is a cisco 800

Alex

3 REPLIES 3
youssef.el.fathi
Beginner

Alex,

For the reloading part, check the config-register. And about your ethernet check the speed/duplex or try another ethernet cable or another interface on your router.

HTH

wouter(config)#interface ethernet0
wouter(config-if)#duplex half
                           ^
% Invalid input detected at '^' marker.

wouter(config-if)#

Can't seem to find any other commands for the duplex settings on the 800 series. Do you guys know what the command is(I have searched but can't turn up anything).

Also same result for the speed command.

Here are the complete details for my interface:

wouter#show interface ethernet0
Ethernet0 is down, line protocol is down
  Hardware is PQUICC Ethernet, address is 0012.807a.7ef8 (bia 0012.807a.7ef8)
  Internet address is 192.168.0.1/24
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 10Mb/s
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 01:48:13, output 00:40:27, 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: random early detection(RED)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     2 packets input, 494 bytes, 0 no buffer
     Received 2 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 input packets with dribble condition detected
     27 packets output, 4419 bytes, 0 underruns
     0 output errors, 0 collisions, 3 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

Since I have used that interface to connect before(using the same nic and cable I'm using now) I can't see how changing ports will help?

hi alex,

ethernet is always and by default half duplex and 10 mbps. is this your WAN port facing the internet? (i suspect it is due to public IP assigned to it). i could see you have an ATM interface and usually for an 800 series router, it has a ADSL/POTS port which you could use for your WAN. i would suggest to work this out with your ISP.

for the blank config after reload, kindly post your show version output. make sure your config reg is set to 0x2102.