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Poor design need redundancy 3750x

Steve Sage
Level 1
Level 1

All switches are 3750x and in different buildings. Users connected to Switch 3 cannot ping servers on Switch 2 that is connected directly with fibre, when Switch 2 looses connectivity with Switch 1. Switch 1 is connected directly to switch 2 with fibre and is the master switch. VTP is used. Internet access is from switch 2. The system is running 24/7 so what simple changes can I make to ensure that users on switch 3 can access servers and internet on switch 2, when switch 1 is off?

Any ideas would be welcome, Thanks, Steve.

7 Replies 7

Joseph W. Doherty
Hall of Fame
Hall of Fame

You'll need to better describe your topology, as 3750Xs are L3 switches.  Are the links L2 or L3?  If L2, are they trunk links?  Also if trunk links, and manual or VTP pruning?  Are the switches running at L2 or L3, etc.?

Thanks, below are the three config files, Steve

There's no description for interfaces, so it will be better to add network diagram. Because your explanation about topology is not clear.

 

Rgrds

Thanks, I think the answer may be to add the vlan default gateway of 192.168.1.251 to switch 3 instead of the master switch, so if the master switch is unavailable users in building 3 can still get to their servers and internet. However the servers are on the 10 vlan and the gateway for that is on the master switch, and should their be a ip route on every switch ? I have to make this system more redundant! Regards, Steve. See attached plan

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Ah, between your config files and drawing, the issue you describe is to be expected.  Your switch 1 is doing the VLAN routing, so if connectivity is lost to it, your other switches' hosts will not be able to get off their VLAN.

What can you do about this?  Well you can also route on switch 2; use HSRP for gateways on both switches 1 and 2.  Do be aware, if you do this with you current logical topology, you might set yourself up for unicast flooding.

Thanks, so how is the also route on switch 2 option done? Because I have severs on both switch 1 and 2 are on the same vlan!

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Each switch would have its own SVI on the same VLAN.  Logically, two routers on the same VLAN.

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