Dynamic routing issue

[Bruno Silva]

Hello,

well, my question is: I have one central route (Cisco Catalyst 3750G-48TS-S) and twenty Switch with layer three ios (Cisco 3560G-24) conected in star topology....

What i want to know is, how central router can communicate with just another router (Cisco 1841) that is behind any 3560G layer three switch?

the cisco 1841 is always the same router that could be behind any other cisco 3560G switch.

Thanks a lot for your patience!

Bruno

[Bruno Silva]

I rate all of your posts!

[John Blakley]

Thank you Bruno!!

HTH,
John

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[Bruno Silva]

You're Welcome! Is a pleasuere to discuss these issues with you and Jon. I learn a lot and every day i'm wondering how it´s possible people like you and Jon devote your time to help and teach. Every simgle person should thank you for everything!

John, yesterday i said to you that was not possible to ping SVI one the same switch... but it is. i deactivated ip routing and reactivating and it's solved.;) today i'll try your script with anxiety!

Did you see my question about curiosity above?

Bruno

[John Blakley]

Bruno,

Another curiosity..... Would you design a network like this on the same  way, or you'll use another dynamic routing protocol like ospf or rip...?

This one? I missed it in all honesty! I don't think the way the design is would help with what type of routing protocol you use. Because the vlan is allowed over the trunk, the interface will be up so any routing protocol would advertise it. I think you're fine with eigrp.

HTH,
John

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[Bruno Silva]

But there is any way?

I can´t believe that is no way to solve it. Other topology, other ip addressing... anything.

Cisco is so powerfull that i can´t imagine a scenario like that with no solution.

Bruno

[John Blakley]

The problem is, as Jon stated earlier, that the Wimax device is connected to the switch and the trunk that the router belongs to is part of that trunk. That allows the interface to be up/up when then means the routing protocol can advertise for it.

I don't have experience with the WiMax equipment, but I think Jon also suggested above that you could put your wimax equipment on a routed port, if that's possible. That would change your design completely. I understand the 1841s are mobile, but why do you connect them directly to the wimax? Does the wimax act like a switch? What is the router used for? If the wimax is a bridge, I have sites (we use Proxim bridges) that are miles away that don't have routers, but instead use a proxim bridge and a switch. I have vlans split off for voice at the remote locations and they all work fine over the bridge without a router.

HTH,
John

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[Bruno Silva]

A routed port? what do you wanna mean? Put wimax equipment on fixed site in a router?

Yes the 1841s are mobile. The router have a 3g board.....

Yes, wimax act like a switch. Just to bridge the respective vlan.

The router is used  for routing is vlan. Are you saying that i don´t need router to bridge the vlan of the mobile station??!?

[John Blakley]

I'm not sure how the wimax equipment works, but a bridge is supposed to extend your lan like an invisible cable. The bridges that we use pass all vlans by default, so when I create a vlan at the remote site, I don't have to change anything on the Proxims to see the new subnets. They route using the L3 switch, or router depending on the site, to route.

I'm still not clear why the 1841 is mobile. Why do you send it to a site? I really need a good, simple diagram of how your site, with the wimax equipment, communicates to your central location. I seem to remember that you have a 7000 series router somewhere. Where is that and what part does it play?

HTH,
John

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[Bruno Silva]

Yeh, bot h wimax equipment are working in a bridge mode with objective of being an invisible cable.

1841 is part of a mobile station....

Simple diagram next:

        The goal of network is this mobile station #1 could be on any fixed station.... and any mobile station from 1 to 8, can connect to any fixed station.

[John Blakley]

Bruno,

My first thought is that you don't need the 1841 at all. The 3560 can do the routing for you if you need to support multiple vlans.

Here's the way that I do it with our equipment:

Router --- L3 switch with vlans ---- edge switch ----Proxim bridge    <----------->  Proxim bridge ----- edge switch ---- hosts

The L3 switch (3560 at your fixed site in your case) has the vlans on them. The edge switchport is trunked on both ends towards the L3 switch and the bridge. On the other side, I don't use a router because there's no need. The bridges communicate all vlans, and the remote site is on the same subnet as the local site.

Even if you changed your topology though, I don't think you're going to get around the issue with eigrp. I don't use routing protocols between my site, so that's where our layouts are different. If it's been working for you, I wouldn't make any major changes if you don't see an immediate benefit just from looking at it.

Are the wimax, 3560, and 1841 all mobile? Do you ship those to different places?

HTH,
John

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[Bruno Silva]

On 3560 of mobile station i don´t need multiple vlan. Just his local vlan.

Yap, in the side of mobile unit i have one 3560 L2, a 1841 router and a wimax equipment. I have 8 mobile stations that can connects to any fixed stations.

I don't understand this paragraphs very well:

The L3 switch (3560 at your fixed site in your case) has the vlans on  them. The edge switchport is trunked on both ends towards the L3 switch  and the bridge. On the other side, I don't use a router because there's  no need. The bridges communicate all vlans, and the remote site is on  the same subnet as the local site.

Even  if you changed your topology though, I don't think you're going to get  around the issue with eigrp. I don't use routing protocols between my  site, so that's where our layouts are different. If it's been working  for you, I wouldn't make any major changes if you don't see an immediate  benefit just from looking at it.

[John Blakley]

I guess to summarize, I'm basically saying that you're extending your lan, so a router isn't really needed. So, you have a L2 switch at each site. Is that where you are saying you have 1 vlan for each site and a unique subnet for each site, or do you have the same subnet/vlan for each site? I guess my question is are these 8 sites up all at the same time?

HTH,
John

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[Bruno Silva]

At maximum i can have any 2 mobile stations at any fixed station.

[Bruno Silva]

[John Blakley]

Thanks for that! That's quite a complicated setup. Try the script if you can and see if it works for you...

HTH,
John

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