Connectivity depending on ping

[TaylorDavidI]

We are having an interesting issue in our office. We use two gateways on the same segment depending on the department for which the computer is used; one is a Windows Server 2003 system running routing and remote access. The other is a RouteFinder "network appliance".

When trying to connect to the web interface on one of our servers using the RouteFinder as the gateway we aren't able to open the page either by DNS name or IP address. If we send a ping to the server we get responses and then are able to connect but after about 20 minutes the connection drops and we must ping again.

The server is on a separate subnet within the building and both of the gateways we use route traffic to it in the same manner. Can anyone give me an idea of where else to look for my answers?

When using the windows server as the gateway none of the problems occur. The same sort of thing happens when attempting to connect through one of our VPNs which have the same route on both systems, the anyone using the routefinder can't connect anyone with the windows server can.

David I. Taylor
A+, Network+, MCP Windows XP

 

[dearingkr]

Frist off, I don't think anyone here can give you a definitive answer without more detailed information.

But generally speaking, it sounds like a basic routing issue.
1. How are the computers configured regarding subnet and default gateway?
2. Which device is the default gateway?
3. Are you running routing protocols or static routes?
4. What are the 2 gateways (Win2k3 Svr & Routefinder) default gateway?
5. How are the destination serves configured regarding routing?

Remember, routing is a two-way street. Not only do your computers need a route to the destination, but the destination servers also need a route back to the source computers.

MCSE CCNA CCDA

 

[TaylorDavidI]

I originally posted this in the "DNS/BIND/DHCP/WINS Issues" forum but had no answer for several days so I tried to post here. I have since had some help from that forum but the issue is not yet resolved, mostly because I am having trouble getting the go ahead from my boss to proceed with the probable fix (a firmware update).

I will answer your questions anyway:

1. The workstations are on a privately addressed subnet of 192.168.0.0 with a mask of 255.255.252.0.

2. Some use the RouteFinder as their default gateway (these are the problem systems) and others use the windows server (these systems do not have any problems).

3. Both systems use static routes as there is are very limited ways to get outside our network. Also, both are using the exact same static routes.

4. The windows server uses the RouteFinder as it's default gateway (but has static routes for internal trafic (including the server we are trying to reach) the RouteFinder uses our ISP's modem as it's default gateway.

5. Unfortunately that is information I can't get at, the server we are trying to get at is our Nortel CCMA server and we don't have access to those settings for it or the router between us (where both the RouteFinder and Windows server point).

I'll try and give a rough picture of the network.

W2K Server
|
{ISP}---RouteFinder---{LAN}---Nortel Router----CCMA

Very rough I know but basically 3 routers off our network. The RouteFinder for external trafic, The W2K Server with only 1 NIC to sort out whether trafic is internal or external and Nortel's router to seperate their ELAN from out LAN.

As I say my boss agrees that the issue may be with an out of date firmware on the RouteFrinder but there are so many other changes going on in the office right now we don't want to complicate trouble shooting by introducing another source of possible problems.

If you have any other ideas that don't involve taking the routers off-line to fix then let me know,

David I. Taylor
A+, Network+, MCP Windows XP

 

[dearingkr]

While a firmware update may well resolve your problem, I would suggest:

It is usually not a good idea to have multiple default gateways. If your routing is sound, they are not necessary.

I would take one of the problem computers and change the default gateway to the W2k3 server and see what happens.

One other thing I just noticed.
You say that when the problem occurs you cannot open pages by DNS name or IP. When you send a ping to temporarily fix it, are you pinging the DNS name or IP? Is the DNS resolving properly?

MCSE CCNA CCDA

 

[TaylorDavidI]

DNS is resolving properly, we ping by name not by IP.

I agree that a situation with fewer routers would be more ideal but this is the way things were done to get other things running properly in the office before I started working here. I'd like to rework all the systems now into a better situation but getting that approval will be difficult.

David I. Taylor
A+, Network+, MCP Windows XP