Administering TCP/IP
Managing the Open Shortest Path First (OSPF) protocol
MAX Administration Guide
7-39
The output includes the following fields:
Multipath routing
A MAX unit running OSPF can alternate between two equal-cost gateways. When OSPF
detects equally good gateways, in terms of routing costs, it puts each equal-cost gateway on an
equal-cost list. The router alternates between the gateways on the list in what is called
equal-cost multipath routing.
The M in the Flg column indicates an equal-cost multipath. A Traceroute from Router A to
example.com
would produce the following display:
ascend% traceroute -q 10 example.com
traceroute to example.com (10.174.88.1), 30 hops max, 0 byte packets
1 C.example.com (10.174.88.13) 20 ms B .example.com (10.174.88.12)
20 ms C.example.com (10.174.88.13) 20 ms B .example.com
(10.174.88.12) 20 ms 20 ms C.example.com (10.174.88.13) 60 ms 20 ms
B .example.com (10.174.88.12) 20 ms C.example.com (10.174.88.13) 20
ms B .example.com (10.174.88.12) 20 ms
2 example.com (10.174.88.1) 20 ms 20 ms 20 ms 20 ms 30 ms 20 ms
20 ms 30 ms 20 ms 30 ms
Notice the alternating replies. The replies are statistically dispatched to Router B and Router C,
with roughly 50% of the packets sent through each gateway. (For background information
about the routing table and about the Traceroute command, see the Network Configuration
Guide for your unit.)
Fields
Description
# Router-LSAs
Number of router link advertisements that are also Type-1 Link State
Advertisements.
# Network-LSAs
Number of network link advertisements that are also Type-2 LSAs.
# Summary-LSAs
Number of summary link advertisements that are also Type-3 LSAs.
Type-3 LSAs describe routes to networks.
# Summary
Router-LSAs
Number of summary link advertisements that are also Type-4 LSAs.
Type-4 LSAs describe routes to AS boundary routers.
# AS External-
LSAs (type-5)
Number of AS external link advertisements which are also Type-5
LSAs.
# AS External-
LSAs (type-7)
Number of ASE-7 link advertisements that are also Type-7 LSAs.
Intra-area
routes
Number of routes with a destination within the area.
Inter-area
routes
Number of routes with a destination outside the area.
Type 1 external
routes
Number of external Type-1 routes that are typically in the scope of
OSPF-IGP.
Type 2 external
routes
Number of external Type-2 routes that are typically outside the scope
of OSPF-IGP.