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Cisco 857 Ethernet0 wont stay up unless constant ping is done.

This is so very strange. My Cisco 857 router has been working perfectly for the last 9 months or so. I configured it 9 months ago and i have touched it since. Yesterday the ethernet port (VLAN1) kept going down all day long for some reason. I figured out that if I let a ping program run, ping -t 10.1.1.50, on a pc, the ethernet port would stay up. Once I stopped pinging the router the ethernet port would go down about 2 minutes later. When I say that the ethernet port would go down what I mean is that it would not respond to a ping, it would just time out and the ethernet port light on the router would stay on like nothing was wrong. I'm completely lost on this one!!!!!! Below is my current running config:

Building configuration...

Current configuration : 5525 bytes ! version 12.3 no service pad service tcp-keepalives-in service tcp-keepalives-out service timestamps debug datetime msec localtime show-timezone service timestamps log datetime msec localtime show-timezone no service password-encryption service sequence-numbers ! hostname bellsouth.net ! boot-start-marker boot-end-marker ! logging buffered 51200 debugging logging console critical enable secret 5 $1$ghu0$fmHrW6.2x8DW5q3XCG8cP1 ! username miamidsl privilege 15 secret 5 $1$N1KI$Eb43d3jltzi4.f9NAwVBH. username ericb secret 5 $1$PIg/$zyHw8QlRA7M0TRllf4iF30 clock timezone PCTime -5 clock summer-time PCTime date Apr 6 2003 2:00 Oct 26 2003 2:00 aaa new-model ! ! aaa authentication login default local aaa authentication login sdm_vpn_xauth_ml_1 local aaa authentication login sdm_vpn_xauth_ml_2 local aaa authorization exec default local aaa authorization network sdm_vpn_group_ml_1 local aaa authorization network sdm_vpn_group_ml_2 local aaa session-id common ip subnet-zero no ip source-route ip dhcp excluded-address 10.1.1.1 10.1.1.50 ! ip dhcp pool sdm-pool1 import all network 10.1.1.0 255.255.255.0 default-router 10.1.1.50 dns-server 10.1.1.3 205.152.144.23 lease infinite ! ! ip cef ip inspect name mail-guard esmtp timeout 30 ip tcp synwait-time 10 no ip bootp server ip domain name bellsouth.net ip name-server 205.152.144.23 ip name-server 205.152.132.23 ip ssh time-out 60 ip ssh authentication-retries 2 no ftp-server write-enable ! ! ! ! ! crypto isakmp policy 1 encr 3des authentication pre-share group 2 ! crypto isakmp policy 3 encr 3des group 2 ! crypto isakmp client configuration group remote key chevytre dns 10.1.1.3 205.152.144.23 pool SDM_POOL_1 ! ! crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto ipsec transform-set ESP-3DES-SHA1 esp-3des esp-sha-hmac ! crypto dynamic-map SDM_DYNMAP_1 1 set transform-set ESP-3DES-SHA1 reverse-route ! ! crypto map SDM_CMAP_1 client authentication list sdm_vpn_xauth_ml_2 crypto map SDM_CMAP_1 isakmp authorization list sdm_vpn_group_ml_2 crypto map SDM_CMAP_1 client configuration address respond crypto map SDM_CMAP_1 65535 ipsec-isakmp dynamic SDM_DYNMAP_1 ! ! ! interface ATM0 no ip address no ip redirects no ip unreachables no ip proxy-arp ip route-cache flow no atm ilmi-keepalive dsl operating-mode auto ! interface ATM0.1 point-to-point description $ES_WAN$$FW_OUTSIDE$ pvc 8/35 pppoe-client dial-pool-number 1 ! ! interface FastEthernet0 no ip address no cdp enable ! interface FastEthernet1 no ip address no cdp enable ! interface FastEthernet2 no ip address no cdp enable ! interface FastEthernet3 no ip address no cdp enable ! interface Vlan1 description $ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$$ES_LAN$$FW_INSIDE$ ip address 10.1.1.50 255.255.255.0 ip access-group 101 in ip verify unicast reverse-path no ip redirects no ip unreachables no ip proxy-arp ip nat inside ip virtual-reassembly ip route-cache flow ip tcp adjust-mss 1452 ! interface Dialer0 description $FW_OUTSIDE$ ip address 65.83.180.246 255.255.255.240 no ip redirects no ip unreachables no ip proxy-arp ip mtu 1492 ip nat outside ip virtual-reassembly encapsulation ppp ip route-cache flow dialer pool 1 dialer-group 1 no cdp enable ppp authentication chap pap callin ppp chap hostname snipped-for-privacy@bellsouth.net ppp chap password 0 domco1 ppp pap sent-username snipped-for-privacy@bellsouth.net password 0 domco1 ! interface Dialer1 mtu 1492 no ip address no cdp enable ! ip local pool SDM_POOL_1 10.1.1.200 10.1.1.250 ip classless ip route 0.0.0.0 0.0.0.0 Dialer0 ip route 10.1.2.0 255.255.255.0 10.1.1.100 ! ip http server ip http authentication local ip http secure-server ip http timeout-policy idle 600 life 86400 requests 10000 ip nat inside source static tcp 10.1.1.3 500 interface Dialer0 500 ip nat inside source static tcp 10.1.1.3 1701 interface Dialer0 1701 ip nat inside source static tcp 10.1.1.3 1723 interface Dialer0 1723 ip nat inside source static tcp 10.1.1.1 8476 interface Dialer0 8476 ip nat inside source static tcp 10.1.1.1 8475 interface Dialer0 8475 ip nat inside source static tcp 10.1.1.1 8474 interface Dialer0 8474 ip nat inside source static tcp 10.1.1.1 8473 interface Dialer0 8473 ip nat inside source static tcp 10.1.1.1 8472 interface Dialer0 8472 ip nat inside source static tcp 10.1.1.1 8471 interface Dialer0 8471 ip nat inside source static tcp 10.1.1.1 8470 interface Dialer0 8470 ip nat inside source static tcp 10.1.1.1 449 interface Dialer0 449 ip nat inside source static tcp 10.1.1.1 23 interface Dialer0 23 ip nat inside source route-map SDM_RMAP_1 interface Dialer0 overload ip nat inside source route-map SDM_RMAP_2 interface Dialer0 overload ip nat inside source static tcp 10.1.1.60 3389 interface Dialer0 3389 ! logging trap debugging logging 10.1.1.50 access-list 100 permit ip 10.1.1.0 0.0.0.255 any access-list 120 permit ip 10.1.2.0 0.0.0.255 any dialer-list 1 protocol ip permit no cdp run route-map SDM_RMAP_1 permit 1 match ip address 100 ! route-map SDM_RMAP_2 permit 1 match ip address 120 ! ! control-plane ! banner login ^CAuthorized access only! Disconnect IMMEDIATELY if you are not an authorized user!^C ! line con 0 no modem enable transport preferred all transport output telnet line aux 0 transport preferred all transport output telnet line vty 0 4 transport preferred all transport input telnet ssh transport output all ! scheduler max-task-time 5000 scheduler allocate 4000 1000 scheduler interval 500 end

Reply to
underzen
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Forgot to add that if I power off the router and power it back on the ethernet0 port comes back up and works for a few minutes then goes down again.

Reply to
underzen

Are there any relevant messages in the logging buffer ( show log) ?

Reply to
Merv

A couple of suggestions:-

  1. Duplicate IP address?
  2. You have it appears somewhat compromised security. IIRC port 449 may allow login attempts to Windows (10.1.1.1) for example.

Maybe your network if full of traffic that is not yours?

Reply to
anybody43

Hey all!! Thanks for the responses.

The first thing I look for when something like this happens is for a compromised PC that's connecting to a IRC server for DDoS attacks. This didn't appear to be the case. There was almost no traffic going outbound on the router. There was also almost no traffic on the internal network at the router.

After talking with a guy at work he mentioned that the night before we had a small power surge. So after working with Cisco a bit they concluded that there was an apparent power surge that traveled through the ethernet cable and caused damage to the internal 4 port switch on the router.

I simply plugged in a backup router, older cisco, and everything is fine. No problems at all.

Reply to
underzen

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