Cisco 2600 Config help

D

DigitalPimp

Fred Garvin - Male Prostitue
Joined
Jul 7, 2000
Messages
2,873
I have a 2600 routing between to networks and the routing and broadcasting works fine. Except the router seems to stop routing packets after about 5 minutes of continuous pings from one network to the other. Communication to the devices stops. Communication from on the same network still works, so the router is stopping packets or something. Is there some sorta "keep alive" command I need to impliment or something to that effect? Any info helps.

Thanks
 
First things first--sanitize and post your configs along with a network diagram.

This will give us a much clearer picture of what's going on, without having to play 20 questions down the road.
 
Well I am not on the site with the issue at the moment, my boss just informed me of this tonight. So if you can help out without my configs at the moment so I have something to work with tomorrow that would be cool.

Basically 2 Networks

10.10.10.X/24 and 172.16.0.X/16

They test SCADA PACK devices on the 172 network. Its just for development.

Anyways everything seems to route and work properly except for communication timing out after about 5 mins.

I will post more info tomorrow.

Thanks
 
Here we are:

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
enable secret 5 $1$M3RU$BTEDM1tbMMDsrR.d.56gl0
!
ip subnet-zero
ip dhcp-server 10.10.10.11
!
!
!
interface Ethernet0/0
ip address 10.10.10.4 255.255.255.0
ip helper-address 172.16.0.255
ip directed-broadcast 1
!
interface Ethernet0/1
ip address 172.16.0.1 255.255.0.0
ip helper-address 10.10.10.255
ip directed-broadcast 1
!
interface Ethernet1/0
no ip address
no ip directed-broadcast
shutdown
!
ip classless
ip forward-protocol udp 546
ip forward-protocol udp 547
ip route 0.0.0.0 0.0.0.0 10.0.0.1
ip route 0.0.0.0 0.0.0.0 10.10.10.1
!
!
line con 0
transport input none
line aux 0
line vty 0 4
login
!
no scheduler allocate
end

Any suggestions may be helpfull, Ive made a few changes like adding the ip helper on the 172 side and checged the DHCP server to the proper IP.

Ive also taken out ip route 0.0.0.0 0.0.0.0 10.0.0.1 I had left in there from testing back at the office.
 
If I sh ip arp

In the list I get

Internet 172.16.0.255 0 Incomplete ARPA

What do you think of that?
 
ip helper-address 172.16.0.255

You're directing broadcasts from the 10.0.0.0 to the IP address of 172.16.0.255. Did you intend to do that, or did you intend to send it to the broadcast address of 172.16.255.255?


Internet 172.16.0.255 0 Incomplete ARPA is probably due to the router searching for an ARP but receives no reply from that IP -- which is caused by above.


...this is all speculation of course. :p


btw - what kind of processor usage are you getting? (sh proc cpu)
 
ahh yes, this router needs to forward broadcasts. This is because the devices on the 172 network are given a mac address and the software engineer has created a tool to brodcast and find all the MAC addresses for those devices on the network so that he can give them IP address. I know it defeats the purpose of the router and all but ya...this is what they wanted. So yes that is supposed to be there.

sh proc cpu

Code: 
CPU utilization for five seconds: 0%/0%; one minute: 1%; five minutes: 1%
 PID  Runtime(ms)  Invoked  uSecs    5Sec   1Min   5Min TTY Process
   1          16     54441      0   0.00%  0.00%  0.00%   0 Load Meter
   2         196       107   1831   0.00%  0.05%  0.03%   0 Exec
   3       92397     27636   3343   0.00%  0.03%  0.00%   0 Check heaps
   4         144        59   2440   0.00%  0.00%  0.00%   0 Pool Manager
   5           0         2      0   0.00%  0.00%  0.00%   0 Timers
   6           0         2      0   0.00%  0.00%  0.00%   0 Serial Backgroun
   7          89      9070      9   0.00%  0.00%  0.00%   0 Environmental mo
   8       78345    162238    482   0.08%  0.06%  0.05%   0 ARP Input
   9           4         2   2000   0.00%  0.00%  0.00%   0 DDR Timers
  10           8         2   4000   0.00%  0.00%  0.00%   0 Entity MIB API
  11           0         1      0   0.00%  0.00%  0.00%   0 SERIAL A'detect
  12           4         2   2000   0.00%  0.00%  0.00%   0 Hawkeye Backgrou
  13      422875    270737   1561   0.00%  0.10%  0.23%   0 IP Input
  14        7358     32367    227   0.00%  0.00%  0.00%   0 CDP Protocol
  15           4         1   4000   0.00%  0.00%  0.00%   0 Asy FS Helper
  16           0         1      0   0.00%  0.00%  0.00%   0 PPP IP Add Route
  17           0         1      0   0.00%  0.00%  0.00%   0 X.25 Encaps Mana
  18       10169      4573   2223   0.00%  0.00%  0.00%   0 IP Background
  19        1032      4536    227   0.00%  0.00%  0.00%   0 Adj Manager
  20           0         1      0   0.00%  0.00%  0.00%   0 TCP Timer
  21           0         1      0   0.00%  0.00%  0.00%   0 TCP Protocols
 PID  Runtime(ms)  Invoked  uSecs    5Sec   1Min   5Min TTY Process
  22           0         1      0   0.00%  0.00%  0.00%   0 Probe Input
  23           0         1      0   0.00%  0.00%  0.00%   0 RARP Input
  24        5934      3770   1574   0.00%  0.00%  0.00%   0 BOOTP Server
  25         181      4535     39   0.00%  0.00%  0.00%   0 IP Cache Ager
  26           0         1      0   0.00%  0.00%  0.00%   0 PAD InCall
  27           4         2   2000   0.00%  0.00%  0.00%   0 X.25 Background
  28           0         1      0   0.00%  0.00%  0.00%   0 Socket Timers
  29           0         1      0   0.00%  0.00%  0.00%   0 ISDN Timer
  31           0         1      0   0.00%  0.00%  0.00%   0 ISDNMIB Backgrou
  32           0         1      0   0.00%  0.00%  0.00%   0 CallMIB Backgrou
  33           0         1      0   0.00%  0.00%  0.00%   0 SNMP ConfCopyPro
  34           0         1      0   0.00%  0.00%  0.00%   0 Syslog Traps
  35           0         1      0   0.00%  0.00%  0.00%   0 Critical Bkgnd
  36       12265     34610    354   0.00%  0.00%  0.00%   0 Net Background
  37           0       101      0   0.00%  0.00%  0.00%   0 Logger
  38         168    271752      0   0.00%  0.00%  0.00%   0 TTY Background
  39         112    271757      0   0.00%  0.00%  0.00%   0 Per-Second Jobs
  40        3599     17423    206   0.00%  0.00%  0.00%   0 Net Input
  41          16     54444      0   0.00%  0.00%  0.00%   0 Compute load avg
  42      151894      4535  33493   0.00%  0.06%  0.05%   0 Per-minute Jobs


debug arp gives me this at times, are the broadcasts from the 172 network being stopped at the router? or 'throttled'?
Code: 
3d03h: IP ARP throttled out the ARP Request for 172.16.0.255
3d03h: IP ARP throttled out the ARP Request for 172.16.0.255
3d03h: IP ARP throttled out the ARP Request for 172.16.0.255
 
OK I think i've narrowed it down to the arp cache.
If I manually clear the cache i can ping the device again, losing the first ping because after clearing the cache the router doesnt know where devices are so it does a broadcast and eventually picks the device up.

So i've changed the arp timeout to about 5 minutes to see if that helps, is this a good idea or not?

Ok I've got it figured out, something to do with the devices and the arp-cache so I've set it to a lower value on that interface and the only downfall of this is mroe network chatter.
 
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