When change cisco device

[YeungKinSan]

our company have:

3640, 2610, 2950 had been used lot of years,

how long they can run, and when we need update its.

[Danilo Dy]

They can run until they fail :)

However, you should check the EOS of the products. Some people, replaced them because they don't have enough resources (DRAM and FLASH) to install new IOS.

EOS for 3640

http://www.cisco.com/en/US/products/hw/routers/ps274/prod_eol_notice09186a008032d840.html

EOS for 2610

http://www.cisco.com/en/US/products/hw/routers/ps259/prod_eol_notice09186a008032d4c2.html

EOS for 2950

Let me know what is the exact model of your 2950

[YeungKinSan]

2950 model is:WS-C2950-24

But we had a single point of failer at 3640, because of only one DDN connection. We must prevent this event, so what can i do?

[Danilo Dy]

If uptime is important to you, you have to consider implementing redundancy both in the device and uplink. Even you have back-to-back hardware maintenance, when the device fail it will take hours to recover it.

WS-C2950-24 is not EOS yet.