Solved: Low Memory on Cisco 837 Router

johnlloyd_13 · ‎01-23-2010

hi experts,

i have a cisco 837 router and having this syslog:

*Mar 1 01:39:10.615: %SYS-2-CHUNKEXPANDFAIL: Could not expand chunk pool for ipnat entry. No memory available

i tried to do a show run but can't only a show start can view the router's config. i've search in cisco.com's website and this is due to router's lack of memory. i also did a show ip nat translations and there's a huge NAT translation output. would like to know if i there's a config that can help resolve save memory on doing NAT or should i just replace this router with a big memory.

Jon Marshall · ‎01-23-2010

johnlloyd_13 wrote:

hi experts,

i have a cisco 837 router and having this syslog:

*Mar 1 01:39:10.615: %SYS-2-CHUNKEXPANDFAIL: Could not expand chunk pool for ipnat entry. No memory available

i tried to do a show run but can't only a show start can view the router's config. i've search in cisco.com's website and this is due to router's lack of memory. i also did a show ip nat translations and there's a huge NAT translation output. would like to know if i there's a config that can help resolve save memory on doing NAT or should i just replace this router with a big memory.

John

If the NAT translations are dynamic it might be worth shortening the timeout so that they are freed up more quickly but to be honest unless the timeout is way too long you might well be looking at a more capable router.

Having said that you need to make sure that the translations are valid ie. you do not have an infected host(s) on your LAN that are trying to create many connections back out through the router.

Jon

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Ganesh Hariharan · ‎01-25-2010

hi jon,

thank you for your response. yes, we've implemented dynamic NAT on this router. would like to know the command you're referring to shorten the NAT timeout on the router's cache. or what router model can you recommend that is capable on handling this?

Hi Jhon,

As per the error log there is not enough processor memory left to expand this chunk pool.anyway try to shorten the timeout for nat transalation as suggested by Jon.

Following are the command to configure the nat transaltion timeout after period of non-use.

ip nat translation timeout

When port translation is not configured, translation entries time out after 24 hours. This time can be adjusted with the above command or the following variations.

Hope to help

Ganesh.H

View solution in original post

Jon Marshall · ‎01-23-2010

johnlloyd_13 wrote:

hi experts,

i have a cisco 837 router and having this syslog:

*Mar 1 01:39:10.615: %SYS-2-CHUNKEXPANDFAIL: Could not expand chunk pool for ipnat entry. No memory available

i tried to do a show run but can't only a show start can view the router's config. i've search in cisco.com's website and this is due to router's lack of memory. i also did a show ip nat translations and there's a huge NAT translation output. would like to know if i there's a config that can help resolve save memory on doing NAT or should i just replace this router with a big memory.

John

If the NAT translations are dynamic it might be worth shortening the timeout so that they are freed up more quickly but to be honest unless the timeout is way too long you might well be looking at a more capable router.

Having said that you need to make sure that the translations are valid ie. you do not have an infected host(s) on your LAN that are trying to create many connections back out through the router.

Jon

johnlloyd_13 · ‎01-25-2010

hi jon,

thank you for your response. yes, we've implemented dynamic NAT on this router. would like to know the command you're referring to shorten the NAT timeout on the router's cache. or what router model can you recommend that is capable on handling this?

Ganesh Hariharan · ‎01-25-2010

hi jon,

thank you for your response. yes, we've implemented dynamic NAT on this router. would like to know the command you're referring to shorten the NAT timeout on the router's cache. or what router model can you recommend that is capable on handling this?

Hi Jhon,

As per the error log there is not enough processor memory left to expand this chunk pool.anyway try to shorten the timeout for nat transalation as suggested by Jon.

Following are the command to configure the nat transaltion timeout after period of non-use.

ip nat translation timeout

When port translation is not configured, translation entries time out after 24 hours. This time can be adjusted with the above command or the following variations.

Hope to help

Ganesh.H