The message Low on memory; try again later indicates that there is not enough memory to support creation of an exec process for telnet. It is probably the result of some bug or a memory leak in the code that you are running. I believe that Mohammed is correct that a reload of the router is the short term solution. It will reclaim lost memory and allow you to telnet. In the long term you need to determine why the amount of available memory decreased. Probably the long term solution will be an upgrade of the code that you are running.
mohammed solution is temporarily, i do the same and my problem solved, i have 12.2(15)T14 IOS installed in my router 2620XM. please advised how much the IOS required memory or should i upgrade it. during reboot i didnt find any error regarding memory.
As Rick has pointed out before, this incident is most probably the result of some bug or a memory leak in the code that you are running, and thus you can run into it again, and thus you are strongly recommended to upgrade your code.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...