5304 Routing Question

[rob misz]

Hello, we have two procurve 5304 switches located at separate locations. We created a VLAN on our core switch which is used for our entire server network. This VLAN has RIP routing enabled. Our plans are to create a DHCP and DNS server at the second site that just services that site. We want to keep this server on the same network as the other. The reason for this is that our link between both sites is not reliable and we like to keep both sites up and running if the link goes down.What is recommended in a situation like this.

[Gerhard Roets]

Hi Rob

A bit of a difficult one especially since you do not have a reliable link.

If the link is not reliable, I would avoid stretching a VLAN across it.

Is there a specific reason for keeping the server on the same network ? When you reffer to a network you mean same broadcast domain right i.e. same subnet mask and ip address range ?

Do you want the DHCP and DNS to be redundant backups for one another ? Since they do not need to be on the same network(Broadcast domain to be redundant).

Does both sites have a link to the outside world ( Internet )?

Do clients on both sites share the same physical gateway ?

What kind of link do you have between the sites ?

Sorry for all the questions before giving you an answer :) Those are some things to think about before thinking about the final solution.

[rob misz]

Thank you for replying.The server thatâ s located at the second site is a Child Domain/file/DNS and DHCP server.
The reason itâ s on the same network is because the server was originally located in our data center however higher ups decided to place it at the second site because that site needs to be up and running at all times for emergency reasons. Site 2 switch connects to site 1 for internet access. The clients at the second site do not need access to the web when the link between the two sites goes down. They only need access to the files and database that run on the server. The link between the sites is a gig fiber link however we only have had it for 2 months so their still fixing the problems. The are no plans to bring back the server to the data center if and when everything is up an running correctly.

[Gerhard Roets]

Hi Rob

Ideally : I would try to get that server reconfigured so it can be in the same vlan as the clients on the secondary site, or in a secured vlan should it be required.

Off course you would need to set rip up so that either vlan be propogated to your main site so routing works perfect, on both ends. The way you do it would depend on your config.

Alternatively. If you have an Ethernet wan connection you can simply extend the servers' vlan over that link(This should be done with the help of your telco for that link). Some telco's don't like tagged packets just appearing.

Then you can place the server in that vlan on your remote site.

I am assuming both sites have unique vlan ids :). If they don't you might need to do a bit more detailed planning than a simple forum question. But this should not be to difficult to make effective.

[rob misz]

Could I just setup RIP on both switches for the server VLAN or will this cause issues

[Gerhard Roets]

Well you see that is where it is difficult.

If you just "move" the server without changing IP's that won't help since you have now segmented your ethernet broadcast domain. That is not allowed :)

But if you are going to change the IP of the server etc and put it in a vlan on the remote side yes that is what your idea drives toward.

If site A and Site B use different IP address ranges and subnet masks(different layer 3 networks) in the server vlan. The answer would be yes

If that answer to the question above is no

You will have the server vlan on both sides. If the server vlan uses the same vlan id on both sides and the same ip ranges you can tag that vlan on your inter site link.

You might want to point the server to the 5304 in site B as its default gateway. Since we are assuming it should work if Site B and Site A cannot communicate.

If this does not clear it up then if you can answer the following questions.
1. Vlan id for server in server room
2. Vlan id for server in site B ( Planned placement )
3. Are you going to change any IP setting on the server ?

[rob misz]

Since I canâ t change the address of the server I created a server VLAN with a VLAN ID of 10 at site B. This is the same at site A. I gave that VLAN an IP address and I point the server default gateway to that address. Then I setup RIP. I didnâ t know if this would cause issues in the routing table.

[Gerhard Roets]

Hi Rob

If the server can ping both the Vlan 10 ip's(On both 5300's) all should be fine.

This implies then you have Vlan 10 on your inter site link all should be fine.

RIP won't mess up your routing tables in this case. You might just have a bit of assymetric routing. But in your scenario it does not sound to rough to me.

[rob misz]

Gerhard,
The server can ping both VLAN 10 ip addresses and everyone has access to the server. Thank you for all your help and your prompt responses.