All Cisco-Network Study Notes: Debugging Cartage Application ACLs

Debugging Cartage Application ACLs 78

ACLs can be acclimated to alter cartage on a router. Active debugs on a router is ability arresting and could

potentially use about all arrangement resources, such as anamnesis and processing power. Excessive debugging under

high amount altitude may account abrupt interruptions or in some cases account the accessory to crash. Therefore,

debugging commands charge to be acclimated with acute caution. Afore enabling debugging, audit the CPU load

by application the appearance processes cpu command and verify that acceptable CPU is accessible afore active the

debugs.

One way of abbreviation the appulse of the alter command on a accessory is to use an ACL to selectively ascertain the

traffic belief that needs to be examined. This abstraction does not do any packet filtering; it is acclimated alone for

controlled monitoring. Example 2-9 shows a agreement that enables debugging alone for packets amid the

hosts 10.1.1.1 and 192.168.1.1 application the alter ip packet [detail] command.

Example 2-9. Debugging Cartage Application ACL Example

Router(config)# access-list 101 admittance ip host 10.1.1.1 host 192.168.1.1

Router(config)# access-list 101 admittance ip host 192.168.1.1 host 10.1.1.1

Router(config)# end

Router# alter ip packet detail 101

IP packet debugging is on (detailed) for admission account 101

Caution

On the router console, back debugs are running, usually the router alert is not apparent because debugs

tend to annal actual fast on the animate screen, abnormally back the alter is intensive. However, use the

no alter all or undebug all commands to stop the debugs (Type this command as blind-folded.) For

more advice on cautiously application debugs, visit

http://www.cisco.com/en/US/tech/tk801/tk379/technologies_tech_note09186a008017874c.shtml

Summary

ACLs are the best accepted and bargain adjustment accessible for clarification cartage beyond the network. This

chapter primarily focused on the use of ACLs for cartage filtering. An overview of IP addressing, subnets, and

masks was additionally presented to advice you bigger accept the accomplishing of ACL. A above allotment of this

chapter was adherent to several types of ACLs and their applications. All Cisco IOS software versions are capable

of acknowledging ACLs.

References

http://www.iana.org/ipaddress/ip-addresses.htm

http://www.freesoft.org/CIE/Topics/26.htm

http://www.isoc.org/briefings/021/

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a00800ca7c0.html

http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a00800a5b9a.shtml

http://www.cisco.com/en/US/tech/tk827/tk369/technologies_white_paper09186a00800949b8.shtml

http://www.cisco.com/en/US/tech/tk583/tk822/technologies_tech_note09186a0080094524.shtml

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a008030c799.html#http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a0080080374.html

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801a1a55.shtml

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a0080431056.html

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801afc76.shtml