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Cisco switch not communicating with Load balancing router

terenceward
Level 1
Level 1

Hi all,

My first post on here I believe.

I have an issue here. I have a Cisco network on a ship where I work, I have an Ericsson GSM Access point which picks up local GSM 3G signal and broadcasts it onboard. I have two of these units and they are connected to a D-Link Load balancing router which is in turn connected to a Cisco 3560 Series 8 poe switch.

Each unit is on a different subnet. The Cisco is on the DHCP server from my AD server (Windows 2003 Server) The Load balancing router has no DHCP and the Ericsson units have their own DHCP servers.

On the Cisco switch if I plug in with a laptop I get an IP address for the DHCP on my server. I cannot ping the load balancing router from it. If I connect to the Load balancing router and set a static address for that subnet I can access the internet via the Ericsson units. And if I connect to the Ericsson I can access the Internet.

The Cisco is on a 172.x.x.x subnet and the D-link/Ericsson are on a 192.x.x.x subnet, so I'm assuming there needs to be information in the Cisco i.e. static routing table. This is where I have hit a wall. My Cisco experience is limited and I've been trying to look at the routing table in the switch but I get this reponse

Using show ip route I get this:

Default gateway is 172.16.16.1

Host               Gateway           Last Use    Total Uses  Interface
ICMP redirect cache is empty

It looks to me that there is no routing table at all. I've tried using a few commands to add the address of the load balancing router but there is no change. I'm sure which command to use in fact. I might be looking in the wrwong place?

Anyone any ideas? If you need me to show any info from the switch please give me the command to use to speed this up. Thanks

22 Replies 22

terenceward
Level 1
Level 1

I forgot to mention, the Cisco network uses Cisco Works for management. I'm used to being able to use a web browser to access the switch and view it's workings from there, Cisco seems complicated and over engineered. I'm sure it would be great to use if I knew it... I feel some studying coming on!

Wow I'm surprised I've had noone come up with a solution here? For a Cisco tech it should be an easy fix no?

The short solution is how do I get a Cisco switch talking to another switch on a different subnet? Or how do I enter a static route on a Cisco switch (model listed in original post)?

Using show ip route I get this:

Default gateway is 172.16.16.1

Host               Gateway           Last Use    Total Uses  Interface
ICMP redirect cache is empty

This o/p normally shows that you have ip default-gateway set on the switch and all the routed traffic being send to that IP.

hop on to 172.16.16.1 and see if it can reach 192.x. network.

If you want to add static route on switch, then try ip route x.x.x.x x.x.x.x ,and you may need to issue 'ip routing' command as well. Make sure to test in a maintenanace window as this might cause outage.

hth

MS

Hi there, thanks for the reply. 172.16.16.1 is the IP address of the Cisco router in question. I telnet in and I am unable to ping the load balancing router.

Can you tell me what you mean by , I'm not sure how to implement that? You mentioned IP routing also, this is different to IP route? I'm still new to all things Cisco.

Strange, but I just did show ip route command again and now I get this:

Gateway of last resort is 172.16.254.10 to network 0.0.0.0

     192.168.8.0/25 is subnetted, 1 subnets
O E2    192.168.8.0 [110/20] via 172.16.241.1, 7w0d, Vlan413
     172.16.0.0/16 is variably subnetted, 36 subnets, 3 masks
C       172.16.176.0/24 is directly connected, Vlan115
C       172.16.178.0/24 is directly connected, Vlan141
C       172.16.164.0/24 is directly connected, Vlan142
C       172.16.160.0/24 is directly connected, Vlan114
C       172.16.162.0/24 is directly connected, Vlan140
C       172.16.132.0/24 is directly connected, Vlan194
C       172.16.128.0/24 is directly connected, Vlan174
C       172.16.0.252/32 is directly connected, Loopback254
O E2    172.16.0.253/32 [110/20] via 172.16.240.1, 7w0d, Vlan412
C       172.16.254.0/24 is directly connected, Vlan450
O E2    172.16.0.254/32 [110/20] via 172.16.241.1, 7w0d, Vlan413

Hi,

this means you've renabled  ip routing  and  now you're receiving routes. Now your ping should be successful.

Regards.

Alain

Don't forget to rate helpful posts.

Hi,

Thanks for your feedback, however I've tried to ping the load balancer again and it's still not working. Surly to allow it to talk to a device on another subnet I need to add the subnet to the static route table??

Hi,

if you do a sh ip route x.x.x.x where x.x.x.x is the Ip of load-balancer and you've got an entry then routing is ok on your side but you must have a toute back to your originating subnet on the load-balancer otherwise it can't work.

So take a look at the load-balancer Routing table.

Regards.

Alain

Don't forget to rate helpful posts.

Tried that, it's not in there. Can you tell me the syntax to use to put it in?

CISF99_M1#sh ip route 192.168.50.1

% Network not in table

Hi,

that's the correct syntax, on which device  did you enter this command?

Can you do a traceroute to this IP and post the output ?

Regards.

Alain.

Don't forget to rate helpful posts.

I entered this on the telnet session on the Cisco unit.

Sorry my question about syntax was meant for the other poster who mentioned adding static route.

Hi,

could you post a topology diagram.

issue following on the switch:

-config# no service timestamp debug

config# access-list 199 permit icmp any any      Rem:just make sure this ACL doesn't exist with sh access-list

config# logging buffered debug

# debug ip pack 199

# ping 192.168.50.1 rep 1

# show log

and post output.

Regards.

Alain

Don't forget to rate helpful posts.

Hi, I'm having some problems entering your syntax? Do I type contents after -config#? I've tried both ways but I just get invalid input selected.

the first 2 commands are enterd like this:

switch# config t

switch(config)# "The 2 commands"

then

you can either stay in config mode but prefix the other commands with the keyword do or exit this mode with the exit command and type the other 3.

Regards.

Alain

Don't forget to rate helpful posts.

Ok here goes

CISF99_M1#config t
Enter configuration commands, one per line.  End with CNTL/Z.
CISF99_M1(config)#no service timestamp debug
CISF99_M1(config)#access-list 199 permit icmp any any
CISF99_M1(config)#exit
CISF99_M1#debug ip pack 199
IP packet debugging is on for access list 199
CISF99_M1#ping 192.168.50.1 rep 1

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 192.168.50.1, timeout is 2 se
.
Success rate is 0 percent (0/1)
CISF99_M1#show log
Syslog logging: enabled (0 messages dropped, 131 messages rate-
s, 0 overruns)
    Console logging: disabled
    Monitor logging: level debugging, 0 messages logged
    Buffer logging: level debugging, 1213 messages logged
    Exception Logging: size (4096 bytes)
    Count and timestamp logging messages: disabled
    Trap logging: level notifications, 1060 message lines logge
        Logging to 172.16.10.10, 1060 message lines logged

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