Telnet connection becomes slow 1

[cjasmeet]

I am running a Redhat 9 PC which has 2 NIC cards of the same manafacturer (Realtek). When both the interfaces are up then TELNET to any interface (eth0 and eth1) becomes slow, however when I bring one interface down then this problem is not noticed.

I believe this is due to both NIC cards being of the same manafacturer but again even if this is the case then it should not behave this way.

 

[pansophic]

Are the two interfaces on different subnets? Are you telnetting to the local subnet, or the remote subnet?

I've run numerous machines over the years with the same type of NIC in them on two different LANs and never experienced any trouble with them. Of course it could actually be the Realtek driver. I've had trouble with Realtek in the past.


pansophic

 

[cjasmeet]

Yes, both the interfaces are on different networks. If I do a telnet to any of these interfaces then it takes a long time for session to establish.

What driver would you suggest I should use if not Realtek?

 

[pansophic]

Oh, you mean that it takes a long to time to establish the session, not that the interface slows down.

That is an easy one, the default behavior of inetd is to do a RARP (Reverse address resolutions protocol) request on inbound connections. If your IP address is not in the machine's DNS server (private IPs typically are not) then the application will wait for the RARP requests to timeout before responding to your connection request.

To verify that this is the problem, add your IP to the /etc/hosts file and try again. If it responds immediately, then you have found the issue. As far as correcting it more permanently, I don't recall how to do that, and quick search of the inetd man page doesn't give any hints.

Some options are populating the /etc/hosts file (tedious and not very portable), putting the internal addresses as a zone in your local DNS server (may have to build a DNS server, yuck!), or finding where to disable the IP to hostname conversion (yeah!).

Sorry I can't help you more.


pansophic

 

[cjasmeet]

Thanks man. You saved my lost of time. I just made an entry in /etc/hosts file and now it works like a charm.

Jasmeet

 

[pansophic]

Glad to hear it.


pansophic