12-04-2011 04:07 PM - edited 03-07-2019 03:43 AM
Hello all,
I've come across a VERY odd situation that seems to have just started over the last day.
I've got a 2621 configured as my main gateway to the internet - right now it's obtaining a DHCP ip from a the ISP's proprietary router set to bridged mode.
As of now, I'm unable to ping the internal interface of the router. I can ping external IP's only, even though I have DNS servers listed, i am unable to resolve host names. I'm running a few servers to which people are able to connect to my web server, among other services. I even have a crypto map setup to another 2621 across the country and can ping all internal ips on the other end... I JUST CANNOT PING THE INTERNAL INTERFACE of the router!! It's so frustrating.
I've noticed that when I ping the router during it's boot process (using linux un-interupted) I get a response in a very short window, then dies again. I'll post my config below, ANY help would be greatly appreciated - I'm at my wits end!
Thank you in advance.
Current configuration : 4229 bytes
!
! Last configuration change at 02:34:00 EST Sun Dec 4 2011 by chris
! NVRAM config last updated at 02:36:29 EST Sun Dec 4 2011 by chris
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Limbo
!
boot-start-marker
boot-end-marker
!
logging buffered 4096 debugging
!
aaa new-model
!
!
aaa authentication login default local
aaa authentication login sdm_vpn_xauth_ml_1 local
aaa authorization exec default local
aaa authorization network sdm_vpn_group_ml_1 local
!
aaa session-id common
clock timezone EST -5
clock summer-time EST recurring
no network-clock-participate slot 1
no network-clock-participate wic 0
ip cef
!
!
!
!
no ip bootp server
ip multicast-routing
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
crypto isakmp policy 5
encr 3des
authentication pre-share
group 2
lifetime 28800
crypto isakmp key PASSWORD address XXX.XXX.XXX.XXX no-xauth
!
!
crypto ipsec transform-set STRONG esp-3des esp-sha-hmac
!
crypto dynamic-map SDM_DYNMAP_1 1
set transform-set STRONG
reverse-route
!
!
crypto map Limbo_to_NAT client authentication list sdm_vpn_xauth_ml_1
crypto map Limbo_to_NAT isakmp authorization list sdm_vpn_group_ml_1
crypto map Limbo_to_NAT client configuration address respond
crypto map Limbo_to_NAT 10 ipsec-isakmp
set peer XXX.XXX.XXX.XXX
set transform-set STRONG
set pfs group2
match address 106
!
!
!
!
interface FastEthernet0/0
description ++++ INTERNAL NETWORK ++++
ip address 192.168.1.1 255.255.255.128
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim dense-mode
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
no cdp enable
!
interface Serial0/0
no ip address
shutdown
!
interface FastEthernet0/1
description ++++ INTERNET CONNECTION ++++
ip address dhcp
ip verify unicast source reachable-via rx allow-default 100
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
ip virtual-reassembly
speed auto
half-duplex
crypto map Limbo_to_NAT
crypto ipsec df-bit clear
!
interface Serial0/1
no ip address
shutdown
!
no ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 75.155.56.1
!
!
ip http server
ip http authentication local
ip http secure-server
!
logging trap debugging
logging facility local2
access-list 1 permit any
access-list 1 remark SDM_ACL Category=16
access-list 1 deny any log
access-list 100 remark SDM_ACL Category=2
access-list 100 deny ip 192.168.1.0 0.0.0.127 192.168.1.128 0.0.0.127
access-list 100 permit ip any any
access-list 106 permit ip 192.168.1.0 0.0.0.127 192.168.1.128 0.0.0.127
!
route-map SDM_RMAP_1 permit 1
match ip address 100
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
!
ntp clock-period 17180228
ntp server 209.167.68.100
ntp server 216.234.161.11
ntp server 209.172.32.214
ntp server 205.189.158.228
!
end
12-04-2011 04:42 PM
Chris
Your post says that you have listed DNS servers, but I do not see any name server configuration in the posted config. The interfaces have ip nat inside and ip nat outside, but I do not see any nat configuration in the posted config. Are they really in the config and for some reason you did not post them?
Your post says that you can not ping the internal interface. But you do not tell us whether this is attempting to ping from outside or attempting to ping from inside, or is it both? Clarification would be appreciated.
HTH
Rick
12-04-2011 04:52 PM
Rick,
My apologies - my frustration is getting the best of me. I forgot to mention that I have another 2600 running as DHCP server. All computers attached to the network (after a confirmed MAC Address) is assigned an IP Address along with the DNS Servers 208.67.222.222 and 208.67.220.220.
As for the NAT I didn't post them - right now my ip nat inside is just running some simple port forwarding to different computers inside the network. When pinging the interface, I'm simply trying to ping 192.168.1.1 (fa0/0) from within the network. I'm able to ping all other devices on the network. just not 1.1. The interface is able to ping itself so I'm pretty confident it's not a hardware issue. I'm also able to ping the internal interface from the external interface using an extended ping.
any other questions you might have would be greatly appreciated.
Thank you again in advance.
12-04-2011 04:57 PM
Chris
Thanks for the clarification. Here are some more questions:
- when you are attempting to ping the router from inside, what is the IP address of the host from which you are trying the ping?
- can you ping from this router to the host that is trying to ping?
HTH
Rick
12-04-2011 05:22 PM
Rick, from the router I am unable to ping any other devices on the network. As for pinging the router, all devices from which I attempting are from the same subnet 192.168.1.X/25 however all other devices can ping each other. It's just this one interface...
12-04-2011 05:31 PM
Chris
Can we be a little more specific than 192.168.1.x? In particular can you verify that x is less than 127?
It might also be helpful if you would post the output of show arp from the router.
HTH
Rick
12-04-2011 06:42 PM
I'm not home right now, so I can't post the arp output, but as for which devices I've pinged from:
1.2, 3, 4, 11, 21, 24, 30
Thanks.
12-04-2011 07:00 PM
Chris
I am interested that you have pinged from .1 since .1 is the address of the router.
If the addresses that you are attempting to ping from should all be in the subnet connected to the router interface then the output of show arp would be quite helpful. It might also be helpful if you post the output of show ip interface brief.
HTH
Rick
12-04-2011 09:17 PM
Try turning of CEF and turning it on. Do if after hours or something if its a production network
HTH
12-05-2011 06:40 PM
Thank you for your help guys,
After a write erase, and a reload the router seems to work even though I re-copied the EXACT same config file as before. I'm now able to ping the router like nothing happened...
Thanks again for all your help - I'm sure I'll be back with other questions/problems.
Cheers!
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