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TIP: is your OSPF LSDB consistent ? Check it in 10 seconds (... per router)

[ Edited ]
‎12-03-2010 08:51 AM

OSPF is a link state protocol and every router in an area must have identical Link State Database (LSDB) .

 

Problem: there are some issues with the IGP, you suspect OSPF is not working fine in your multi-vendor network. The OSPF domain is big and you are not able to analyze/compare results of show ospf database from each device. Is the OSPF LSDB consistent ?

 

Solution: OSPF MIB allows you to verify the checksum of OSPF LSDB (sum of all LSA checksums). Per area and for all external link-state advertisements. Get and compare the numbers for all routers/per area.

 

Example:

 

 

// Junos CLI

admin@gw> show snmp mib walk ospfAreaLsaCksumSum
ospfAreaLsaCksumSum.0.0.0.0 = 510116

admin@gw> show snmp mib walk ospfExternLsaCksumSum
ospfExternLsaCksumSum.0 = 426095


// SNMP - any device with OSPF MIB support
// 
// ospfAreaLsaCksumSum == 1.3.6.1.2.1.14.2.1.8 indexed with ospfAreaId 
// 
// ospfExternLsaCksumSum == 1.3.6.1.2.1.14.1.7 single object instance (scalar)

nms:/# snmpwalk -c community 101.0.31.253 .1.3.6.1.2.1.14.2.1.8
14.2.1.8.0.0.0.0 = 510116
nms:/# snmpwalk -c community  101.0.31.250 .1.3.6.1.2.1.14.2.1.8
14.2.1.8.0.0.0.0 = 510116

nms:/# snmpwalk -c community 101.0.31.252 .1.3.6.1.2.1.14.1.7
14.1.7.0 = 426095
nms:/# snmpwalk -c community 101.0.31.253 .1.3.6.1.2.1.14.1.7
14.1.7.0 = 426095


// ospfAreaLsaCksumSum from multi-area OSPF router 

nms:/# snmpwalk -c community 101.0.31.252 .1.3.6.1.2.1.14.2.1.8
14.2.1.8.0.0.0.0 = 488362
14.2.1.8.10.33.0.0 = 1311311

 

P.S. ospfAreaLsaCksumSum and ospfExternLsaCksumSum values will change as LSA are generated/refreshed.

1 REPLY 1
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Re: TIP: is your OSPF LSDB consistent ? Check it in 10 seconds (... per router)

‎09-17-2014 01:39 PM

Accepted Solution

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