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Community Member

Memory Allocation Failed

I have an 1821 router with VPN configured between two sites. On one of the routers i keep getting messages in Log file - "critical memory allocation of 65548 bytes failed from 0x400C615C, alignmet 32. When I do a show buffers the normal buffers, 1548 bytes, shows 1251600 hits, 1307865 misses, 93615 failures. The FE 0/0 also shows lots of misses. The FE 0/0 is the internal LAN. On both routers for FE 0/1 (outside) interface I have put crypto ipsec df-bit clear. Any ideas why I am getting these failures.


Re: Memory Allocation Failed

If they go away for a while after reloading (rebooting) the router, then t's likely to be a memory leak.

What flavor & version of IOS are you running?

Let us know

Good Luck


Community Member

Re: Memory Allocation Failed

Its a 2811 router/fw

IOS 12.4(3e)

After reload problem shows up 10 minute later. Show memory always says there is a bunch of free memory.

any ideas?



Community Member

Re: Memory Allocation Failed

We are also have UPD with fragmented packets


Re: Memory Allocation Failed

Total memory doesn't really tell the story. You need to look at the "Largest Fragment" listing.

As an example (and *not* reality), let's say the router says you have 32M of available memory total, the Largest Fragment is 500K.

When the router tries to run a process that requires more than 500K, you'll get an "Out of Memory" error (or probably a "MALLOC XXXXXX" error - MALLOC is programmer-speak for "Memory Allocation").

When possible, reload the router (reboot) ... and as soon as possible, start an ASCII capture on your terminal emulator and start doing some "Show Memory Summary (sh mem sum) ... keep your eye on the Largest Fragment listing (the top ~3-4 lines of output)and see if it drops rapidly. You may have a corrupt IOS or other failure that doesn't return the memory back into the pool properly (a memory leak).

It may also be helpful to track some "show process and / or sh proc cpu" to see if there is / what is the process that's sucking up your ram.

BTW: I checked the software advidsor: 12.4(3e) is a defarral.

Table Of Affected Software And Replacement Solution

OS Type

Software Affected IOS 12.4(3e)all Platforms

Software Solution Version(s) 12.4(3f) all Platforms

Software(s) Availability (mm/dd/yyyy)


12.4(3f) is the minimum recommended fix.

Good Luck



Re: Memory Allocation Failed

You need to get your router upgraded. Post your show version from the router.


Community Member

Re: Memory Allocation Failed

Thanks for all the help.

I updated the IOS to 12.4(13a) and the problem went away.

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