02-05-2006 03:51 PM - edited 03-03-2019 11:39 AM
I am using a Cisco 1801. I have a /30 network with one static public IP on my end and the other useable IP being the gateway on the ISP's side.
The connection works fine for a few hours, after which it just drops comms and I get no data flow. I'll power cycle the Cisco 1801 and still no data flow, but the CD light is on solid.
The odd thing is that to establish data flow again, I have to remove the Cisco 1801 and plug in a netgear router. I then plug the Cisco 1801 back in and everything works fine for a few more hours. I'm continually having to do this to get the Cisco 1801 to work.
The ISP says it's a layer 2 problem because when my connection goes down they can't see any MAC address coming from my end. Even after power cycling the Cisco 1801, they still can not see any MAC address on my end. When I plug the netgear router in, they then can see a MAC address on my end.
Is it my Cisco 1801 that's the problem or something on the ISP's side?
02-05-2006 05:01 PM
Is it possible that the few hours that it works is 4 hours? If it does run for 4 hours and then fail I would guess that it might be a problem in the ARP cache.
If you could give us some more information, what kind of interface, configuration of the router, pehaps show interface, and maybe show ARP, then we might be better able to see what is causing this problem.
HTH
Rick
02-07-2006 05:18 PM
It doesn't run for four hours and then fail.
Below is the edited show run.
Please find attached the show interfaces, show arp and show version output.
Thanks for everyone's help so far.
-----
#show run
Building configuration...
Current configuration : 4918 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
service password-encryption
service sequence-numbers
!
hostname xxxxxx
!
boot-start-marker
boot-end-marker
!
security authentication failure rate 3 log
security passwords min-length 6
logging buffered 51200 warnings
enable secret xxxx
!
username xxx privilege 15 secret xxxx
clock timezone PCTime 10
clock summer-time PCTime date Mar 30 2003 3:00 Oct 26 2003 2:00
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
no aaa new-model
ip subnet-zero
no ip source-route
!
!
ip cef
ip tcp synwait-time 10
!
!
no ip bootp server
ip domain name see.com.au
ip name-server aa.aa.aa.aa
ip name-server bb.bb.bb.bb
no ftp-server write-enable
!
!
!
interface Null0
no ip unreachables
!
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 ATM0.2 point-to-point
mtu 1457
ip address yy.yy.yy.yy 255.255.255.252
ip nat outside
pvc 1/32
encapsulation aal5snap
!
!
interface BRI0
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip route-cache flow
shutdown
no cdp enable
!
interface FastEthernet0
description Wireless Link$FW_INSIDE$$ETH-LAN$
ip address 192.168.0.2 255.255.255.0
duplex auto
speed auto
no cdp enable
!
interface Vlan1
description 8 Port LAN Switch$ETH-SW-LAUNCH$$INTF-INFO-FE 1$$FW_INSIDE$
ip address 192.168.2.1 255.255.255.0
ip nat inside
ip route-cache flow
!
interface Dialer0
no ip address
no cdp enable
!
router rip
version 2
network 192.168.0.0
network 192.168.2.0
no auto-summary
!
ip classless
ip route 0.0.0.0 0.0.0.0 ATM0.2
ip route 192.168.1.0 255.255.255.0 192.168.0.1 permanent
!
ip http server
ip http access-class 2
ip http authentication local
ip http timeout-policy idle 600 life 86400 requests 10000
ip nat inside source list 1 interface ATM0.2 overload
ip nat inside source static tcp 192.168.2.210 8000 interface Dialer0 8000
ip nat inside source static tcp 192.168.2.210 80 interface ATM0.2 80
!
ip access-list extended sdm_fastethernet0_in
remark SDM_ACL Category=1
remark port-87
permit tcp any eq 87 any eq 87 log
!
access-list 1 remark INSIDE_IF=Vlan1
access-list 1 remark SDM_ACL Category=2
access-list 1 permit 192.168.2.0 0.0.0.255
access-list 2 remark HTTP Access-class list
access-list 2 remark SDM_ACL Category=1
access-list 2 permit 192.168.0.0 0.0.0.255
access-list 2 permit 192.168.2.0 0.0.0.255
access-list 2 permit 192.168.1.0 0.0.0.255
access-list 2 deny any
access-list 100 remark VTY Access-class list
access-list 100 remark SDM_ACL Category=1
access-list 100 permit ip 192.168.0.0 0.0.0.255 any
access-list 100 permit ip 192.168.2.0 0.0.0.255 any
access-list 100 deny ip any any
no cdp run
!
control-plane
!
line con 0
login local
transport output telnet
line aux 0
login local
transport output telnet
line vty 0 4
access-class 100 in
privilege level 15
login local
transport input telnet
line vty 5 15
access-class 100 in
privilege level 15
login local
transport input telnet
!
scheduler allocate 4000 1000
scheduler interval 500
end
-----
02-05-2006 05:04 PM
Hello,
you could try and configure the arp timeout to never timeout:
arp timeout 0
Which IOS version are you running, and what kind of connection do you have to your ISP (e.g. Leased Line PPP, Frame Relay)?
Regards,
Nethelper
02-07-2006 06:11 PM
It's a ADSL connection with one public IP on our end and the gateway on the ISP's end.
#show version
Cisco IOS Software, C180X Software (C180X-BROADBAND-M), Version 12.3(8)YI1, RELEASE SOFTWARE (fc1)
Synched to technology version 12.3(10.3)T2
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Fri 22-Apr-05 15:54 by ealyon
ROM: System Bootstrap, Version 12.3(8r)YH5, RELEASE SOFTWARE (fc1)
ROM: Cisco IOS Software, C180X Software (C180X-BROADBAND-M), Version 12.3(8)YI1, RELEASE SOFTWARE (fc1)
branch-router uptime is 2 days, 1 hour, 11 minutes
System returned to ROM by power-on
System image file is "flash:c180x-broadband-mz.123-8.YI1.bin"
Cisco 1801 (MPC8500) processor (revision 0x200) with 118784K/12288K bytes of memory.
Processor board ID FHK0940115G, with hardware revision 0000
9 FastEthernet interfaces
1 ISDN Basic Rate interface
1 ATM interface
31360K bytes of ATA CompactFlash (Read/Write)
Configuration register is 0x2102
02-05-2006 08:36 PM
You could try using a locally administered MAC address (replace the 1801's MAC with the MAC of the Netgear).
In the cable broadband environment, some providers enforce the use of a single MAC at the destination.
If you originally registered the Netgear as your router, something at the ISP may be trying to keep it as the only valid device.
It's pretty thin, as suggestions go, but if it comes down to the "beat your head against the wall" stage of troubleshooting, give it a shot.
It could also be a flakey 1801 (or interface). Substituting the Netgear gives the 1801 time to cool off so it's ready for another couple hours (then it heats up, flakes out, gets a break , cools off ......).
Make sure there's plenty of "breathing room" around the 1801.
FWIW
Scott
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