We are having data centre with core routers(7507) and core switches(4507) which are always ON.
Now is it recommend to take planned reboot of core devices once in 6-7 months?
If yes is there any supported doc giving such recommendation?
Or we should not do reboot of such core devices?
I would not rebot a production router or switch unless there was a problem you believe a reboot will correct. Keep you closet well ventilated, your equipment dust free and the power on. If your phone doesn't ring because of network problems enjoy the peace.
When Packet magazine was still running, they had a competition for who could find a router the greatest uptime in their networks. It was years and years.
Never touch a running system ...
Rebooting a system imho is only required because of a software/hardware bug, which should first be identified through trouble shooting or because people are running out of ideas while trouble shooting ...
In the latter case you might consider to take some training to get new ideas ;-)
In addition, a reboot in some environments is much more costly than training ...
My 2 cents
P.S.: In case you detect network outages "by telephone" you should seriously consider a redesign of your network management environment and your operational procedures ;-)
It is not recommended to reboot routers/switches unless there is a need to reboot them, i.e. in my case I only reboot them during IOS upgrade/update.
There are ISP's and Data Centre's I know that reboots their routers/switches including other systems regularly. These are some of the reasons.
Reason: Planned quarterly maintenance for the whole year (which is scheduled and announce to their customers as per their internal change management procedure). So when there are no IOS update/upgrade, they reboot the device instead to make sure that the device can reboot and load the current config in case there are scenarios that the device reboot unexpectedly - they take this schedule maintenance to test that.
Scenario: I have experienced that a vendor setup a router for a certain customer but never save the config (the router has been in production for years), when there was a power failure the router rebooted but there was no config to load - end up a long unscheduled downtime which affect the customer SLA to its clients. Its common to people to perform change to the config without saving them while doing some testing (I see this all the time) - and forgot to save them. If you do a scheduled reboot, you will save the config before you reboot it right?