04-24-2008 08:04 AM - edited 03-05-2019 10:35 PM
Hi
Could somone please tell me how I can view the mask of a route advertised in OSPF, whether it is Inter or Intra area routes or External routes. If I run "show ip ospf database" I can see the routes but not their associated masks?
Thanks
Dan
Solved! Go to Solution.
04-24-2008 10:36 AM
Dan,
The information is in the lsdb.
1. For internal routes network type broadcast, you have to look at the lsa type 2:
r6#sh ip ospf dat net
OSPF Router with ID (6.6.6.6) (Process ID 1)
Net Link States (Area 2)
Routing Bit Set on this LSA
LS age: 155
Options: (No TOS-capability, DC)
LS Type: Network Links
Link State ID: 192.168.156.5 (address of Designated Router)
Advertising Router: 5.5.5.5
LS Seq Number: 80000001
Checksum: 0x42AC
Length: 32
Network Mask: /24
Attached Router: 5.5.5.5
Attached Router: 6.6.6.6
r6#
2. For internal routes network type point-to-point, there is stub network associated to the p-to-p that give you that information:
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 6.6.6.6
(Link Data) Router Interface address: 192.168.56.5
Number of TOS metrics: 0
TOS 0 Metrics: 48
Link connected to: a Stub Network
(Link ID) Network/subnet number: 192.168.56.0
(Link Data) Network Mask: 255.255.255.0
Number of TOS metrics: 0
TOS 0 Metrics: 48
3. For inter area routes, the information is in the lsa type 3:
Summary Net Link States (Area 2)
Routing Bit Set on this LSA
LS age: 621
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 2.2.2.2 (summary Network Number)
Advertising Router: 5.5.5.5
LS Seq Number: 80000001
Checksum: 0x4649
Length: 28
Network Mask: /32
TOS: 0 Metric: 145
4. For inter area routes, the information is in the lsa type 5 or 7:
Type-5 AS External Link States
Routing Bit Set on this LSA
LS age: 1359
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 0.0.0.0 (External Network Number )
Advertising Router: 3.3.3.3
LS Seq Number: 80000001
Checksum: 0xE0C5
Length: 36
Network Mask: /0
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 1
Type-7 AS External Link States (Area 1)
Routing Bit Set on this LSA
LS age: 21
Options: (No TOS-capability, Type 7/5 translation, DC)
LS Type: AS External Link
Link State ID: 192.168.255.0 (External Network Number )
Advertising Router: 1.1.1.1
LS Seq Number: 80000001
Checksum: 0xB56F
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 1.1.1.1
External Route Tag: 0
Regards,
04-24-2008 10:36 AM
Dan,
The information is in the lsdb.
1. For internal routes network type broadcast, you have to look at the lsa type 2:
r6#sh ip ospf dat net
OSPF Router with ID (6.6.6.6) (Process ID 1)
Net Link States (Area 2)
Routing Bit Set on this LSA
LS age: 155
Options: (No TOS-capability, DC)
LS Type: Network Links
Link State ID: 192.168.156.5 (address of Designated Router)
Advertising Router: 5.5.5.5
LS Seq Number: 80000001
Checksum: 0x42AC
Length: 32
Network Mask: /24
Attached Router: 5.5.5.5
Attached Router: 6.6.6.6
r6#
2. For internal routes network type point-to-point, there is stub network associated to the p-to-p that give you that information:
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 6.6.6.6
(Link Data) Router Interface address: 192.168.56.5
Number of TOS metrics: 0
TOS 0 Metrics: 48
Link connected to: a Stub Network
(Link ID) Network/subnet number: 192.168.56.0
(Link Data) Network Mask: 255.255.255.0
Number of TOS metrics: 0
TOS 0 Metrics: 48
3. For inter area routes, the information is in the lsa type 3:
Summary Net Link States (Area 2)
Routing Bit Set on this LSA
LS age: 621
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 2.2.2.2 (summary Network Number)
Advertising Router: 5.5.5.5
LS Seq Number: 80000001
Checksum: 0x4649
Length: 28
Network Mask: /32
TOS: 0 Metric: 145
4. For inter area routes, the information is in the lsa type 5 or 7:
Type-5 AS External Link States
Routing Bit Set on this LSA
LS age: 1359
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 0.0.0.0 (External Network Number )
Advertising Router: 3.3.3.3
LS Seq Number: 80000001
Checksum: 0xE0C5
Length: 36
Network Mask: /0
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 1
Type-7 AS External Link States (Area 1)
Routing Bit Set on this LSA
LS age: 21
Options: (No TOS-capability, Type 7/5 translation, DC)
LS Type: AS External Link
Link State ID: 192.168.255.0 (External Network Number )
Advertising Router: 1.1.1.1
LS Seq Number: 80000001
Checksum: 0xB56F
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 1.1.1.1
External Route Tag: 0
Regards,
04-25-2008 05:21 AM
Just for the record, point number 4 should have said "for external routes" rather than "for inter area routes".
Regards,
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