Two routers and two IPs on one LAN

J

Jay O'Brien

I need some help with my two-IP LAN.

My ZyXEL DSL modem feeds a Netgear DS104 hub. The hub feeds
two Linksys BEFSR41 routers. One router is set up as one of
my IPs, the other router is on my second IP.

One Router feeds an eight port Linksys EZXS88W switch. Four
computers, three running XP Pro and one Win98SE, are plugged
into the switch. Those computers access one of my IPs for
internet access, and can share files (I use NetBEUI for file
sharing).

The other router feeds a computer that accesses the second
IP for internet access. It is an Amateur Radio "ar-cluster"
node that is accessible via amateur radio locally.

All of the "permanent" computers (described above) have
static IPs in the 192.168.1.x range and none are duplicated.
One router is set as gateway 192.168.1.1 and the other
router is set as 192.168.1.2.

I have a test notebook computer that is set up to obtain
its IP automatically, and I have the DHCP addresses provided
by the two routers set to different ranges that don't overlap.
I can plug the notebook in to either router and it works as
expected.

I want to be able to connect the two LANs together on occasion
for file sharing or combined logging of the Router logs while
maintaining the isolation on a general basis for security.

If I connect the LAN side of the two routers together, using a
crossover cable or connecting an "uplink" port to a user port
on the other router, they go crazy. Lights flashing like mad. If,
however, I connect the router that doesn't feed the 8-port switch
to an outlet on the 8-port switch, all is well for a long time,
often an hour or more. The LAN sides of the two routers are
connected through the 8-port switch; they are not connected to
each other directly.

When the two LANs are so connected, from any computer I can get
to the control page on either router by just specifying the
router's IP. I can turn logging on in both routers and capture
the linksys logging stream in the wallwatcher program, and it
reports the local IP addresses correctly, accepting data from
both routers. I can change the gateway address in the TCP/IP
protocol on a computer and direct an internet connect to either
IP by virtue of sending it to the proper router IP on the LAN.

With the LANs connected through the switch, if I shut down a
computer (or sometimes when I do nothing!) the LANs go into a
loop with what Network Probe says are ARP protocol messages; if
I leave it in this flashing-lights condition long enough I have
to reset a router to get it to talk on the internet again.

I suspect that if I knew the proper way to set subnets and
select LAN IP ranges that this would work fine.

Any guidance will be most appreciated.

Jay O'Brien
Rio Linda, CA USA
 
R

Robert L [MS-MVP]

sounds like routing order issue. posting routing table here may help.

--
For more and other information, go to http://www.ChicagoTech.net

Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Robert Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
 
J

Jay O'Brien

I don't understand. Which routing table are you referring to?


-------- Original Message --------
Subject: Re: Two routers and two IPs on one LAN
Date: Fri, 3 Oct 2003 08:04:02 -0500
From: Robert L [MS-MVP] <[email protected]>
Newsgroups: microsoft.public.windowsxp.network_web
References: <OIAR#[email protected]>

sounds like routing order issue. posting routing table here may help.

--
For more and other information, go to http://www.ChicagoTech.net

Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Robert Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
 

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