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New Member

192.168.10.x address range


This is probably a stupid question. I know (or at least I think I know or understand it) that the private IP addresses such as 192.168.10.x are normally not routed by routers.

I'm trying to setup a CISCOPro 765 router to dial over ISDN into a partner company. They gave me the IP address of their server, the ISDN number, username etc...

The setup itself is no problem, I can build the connection over ISDN, authenticate etc... But I cannot ping to their server. I think it is caused by the fact that their server has IP address, and that the router is filtering these packets going out.

Now I have 2 questions:

1. Is my diagnose correct? (The fact that it is not working because these packets are not routed due to the destination IP address?)

2. Is there a way around this with the router we have?

Best regards,

Eddy Steevens

New Member

Re: 192.168.10.x address range


Routers in the Internet won't route traffic to private address space but they necessarily route to those addresses in private networks. So you probably just need some static/default routes setup on both sides of the connection.


New Member

Re: 192.168.10.x address range

It doesn't sound like you are connecting to the internet at all here.

I would suspect 1 thing in this senario.

1. Routing

Either you do not have the routing set up correctly, or they do not. Check this carefully.

Your server------CiscoPro765-------ISDN-------Their Router-------Their Server

Your server should have the address pointed at the CiscoPro's ethernet. Their server should have pointed at "Their Router's" ethernet interface.

New Member

Re: 192.168.10.x address range

Yes it is right, we are connecting to a private network not the internet. From an other reply I understood that the private address range is not routed when we're talking about the internet, but when we're talking about a private network then it should go through.

On Our 'server' side (NT workstation) I have setup the default gateway to the CiscoPro's ethernet. If I ping from that machine to the their server's address (, the router opens up a ISDN connection as it should. But I get no reply from the their server. Based upon you answer I'd suspect the routing table setup of their server (I think their server side is a linux server and I also think that no router is involved there, just the linux server). I have enabled the packet logging of the cisco router (log packets verbose or something like that). If I look at the output of that, I only see lines where the 'Flt:' count has some number and all the other values have 0 behind it. So I was guessing that the router filtered the packets out and the problem was at our side. I do not know much about cisco routers so I have used the Cisco Fast step software to setup the router and I have selected that we are connecting to 'a unlisted ISP or corporate network' after that I selected connecting to 'remote corporate network only'. So I guess that the setup is done properly for a corporate network and not for internet use. So the private address range should not be filtered out. But again I may be wrong here.

Any more suggestions?

Thanks in advance

New Member

Re: 192.168.10.x address range

it could be routing on there side or it could be that the packets aren't "interesting" enough to get sent through the isdn. Without seeing the configs on both sides it is hard to tell.

New Member

Re: 192.168.10.x address range

I dont feel you're using as a external connection. However, if you are connecting thru internet you have nat the ip to public ip address on remote end. If not , check your routing table and see if you have static or dnymaic route in the router. Also, make sure server has default gatway. Hope fully it help you some. If not feel free to contact me.

New Member

Re: 192.168.10.x address range

wait a second, there is no router on their side? how are you dialing into them then? is there some kind of isdn card or serial device on the linux server? have then do a "netstat -r" to see if your server's address is in the routing table of the linux server.

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