[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: understanding Routing Cisco vs. Linux



Forwarded email.

--- Begin Message ---
Hi Thedore

On Thu, Sep 26, 2002 at 09:08:26AM -0400, Thedore Knab wrote:
> I am trying to reduce latency, reduce peer to peer bandwidth 
> hogs, and do some stateful firewalling while I am at it.


> Here is the part I am need to worry about.
> 
> ip classless
> ip route 192.146.226.0 255.255.255.0 FastEthernet0/0
> ip route 209.243.33.0 255.255.255.0 FastEthernet0/0
...
> ip route 209.243.34.0 255.255.255.0 FastEthernet0/0

Your provider probably should have done some supernetting
rather than listing all these /24s.. but that is a nicety
(I hope he ISNT annoucing them as /24s! into the BGP).

By the looks of it you aren't using ANY vlans..
as the router is dumping all the packets onto the local
fast ethernet.
(the config on the 5500 would interest me).
What you might want to try and do is setup 802.1Q between
the Cat 5500 and your linux box.

You will then need a transfer network between the linux box and
the cisco.

The Linux box interface connected to the Cat 5500 should look like
multiple 'sub interfaces' (havent used the 802.1q on linux so dont
know exactly how its implemented). 

This will effectively turn your box into a router with 'X' interfaces
(one into each vlan on the switch), and all traffic between ports will
go over the linux box.

(to be honest, it would probably be easier taking control of the 7200
and not botherring with the linux box).

A sample config with a linux box

  Internet
     |
     |
   C7200
       192.168.0.1/28   (you should probably use NON RFC addresses here)
     |
     |
       192.168.0.2/28
    Linux
      Vlan 1 x.x.x.1/24
      Vlan 2 x.x.y.1/24
      Vlan 3 x.x.z.1/24
     |
     | Trunk    
    C5500  
     |
     |---Server in Vlan1
     |
     |---Server in VLan2
....

and on the cisco 7200 route your networks to 192.168.0.2...
and the servers in Vlan one use the default route of x.x.x.1, 
                   vlan 2                            x.x.y.1, etc


but as I said, consider using the 7200 to do this.

Andrew

--- End Message ---

Reply to: