Hi All,
I'm trying to redistribute BGP into EIGRP. I have two groups of subnets and I'm applying different metrics to each group. the reason for this is there are a total of four routers providing access from the WAN into the core network. The issue I'm seeing is when I view the topology table at the core which is one hop away the delay doesn't always match the configured delay + the link delay. The link delay is consistently 10microseconds. There are about 100 subnets being redistributed and about half the subnets show the correct delay while half do not. I'll provide the topology tables for two subnets so you can see the difference in the Delay.
WAN router 1
router eigrp 100
network 172.24.0.0
network 172.31.0.0
redistribute bgp 65001 route-map bgp-to-eigrp-redist
access-list 65 remark route-map bgp-to-eigrp-redist define specific routes for outbound load balancing
access-list 65 permit 172.23.128.0 0.0.31.255
route-map bgp-to-eigrp-redist permit 10
match ip address 65
set metric 10000000 10 0 1 1
!
route-map bgp-to-eigrp-redist permit 20
match ip address 70
set metric 10000000 40 0 1 1
!
route-map bgp-to-eigrp-redist permit 30
set metric 10000000 10 0 1 1
show ip bgp
# some output removed
# Next hop should be 10.99.101.1
*> 172.31.131.0/24 172.24.120.169 11008 32768 ?
* 10.99.101.1 0 2056 65130 i
* i 172.24.120.201 10752 100 0 ?
* i 10.99.101.13 0 100 0 2056 65130 i
* i 10.99.101.5 0 100 0 2056 65130 i
* i 172.31.132.0/24 10.99.101.9 0 100 0 2056 65132 i
* i 10.99.101.13 0 100 0 2056 65132 i
*> 10.99.101.1 0 2056 65132 i
* i 10.99.101.5 0 100 0 2056 65132 i
WAN router 2
router eigrp 100
network 172.24.0.0
network 172.31.0.0
redistribute bgp 65001 route-map bgp-to-eigrp-redist
access-list 65 remark route-map bgp-to-eigrp-redist define specific routes for outbound load balancing
access-list 65 permit 172.23.128.0 0.0.31.255
access-list 70 remark route-map bgp-to-eigrp-redist define specific routes for outbound load balancing
access-list 70 permit 172.31.192.0 0.0.31.25
route-map bgp-to-eigrp-redist permit 10
match ip address 65
set metric 10000000 40 0 1 1
!
route-map bgp-to-eigrp-redist permit 20
match ip address 70
set metric 10000000 10 0 1 1
!
route-map bgp-to-eigrp-redist permit 30
set metric 10000000 40 0 1 1
Core switch
# two 10gig links between core and WAN router each with a delay of 10 microseconds
# two alternate routes have been removed from the topoly table, these offered a better metric than WAN router 1
# The delay in the route entry is correct, 400 mico seconds for the redistribution metric and 10 microseconds for the actual link.
# The prefered route which should have a delay of 110 microseconds isn't even advertised.
#sh ip eigrp topology 172.23.131.0/24
EIGRP-IPv4 Topology Entry for AS(100)/ID(172.26.254.9) for 172.23.131.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 10752
Descriptor Blocks:
172.24.120.178 (GigabitEthernet1/1/42), from 172.24.120.178, Send flag is 0x0
Composite metric is (13056/10240), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 410 microseconds # This delay is correct (400microsec redist delay + 10microses for link delay)
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.13
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
172.24.120.186 (GigabitEthernet2/1/42), from 172.24.120.186, Send flag is 0x0
Composite metric is (13056/10240), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 410 microseconds # This delay is correct (400microsec redist delay + 10microses for link delay)
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.13
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
#This output matches what's been configured. Note the delay is the configured redistribution delay plus the link delay of 10 microseconds
#sh ip eigrp topology 172.23.132.0/24
EIGRP-IPv4 Topology Entry for AS(100)/ID(172.26.254.9) for 172.23.132.0/24
State is Passive, Query origin flag is 1, 2 Successor(s), FD is 5376
Descriptor Blocks:
172.24.120.162 (GigabitEthernet1/1/41), from 172.24.120.162, Send flag is 0x0
Composite metric is (5376/2560), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 110 microseconds # This delay is correct (100microsec redist delay + 10microses for link delay)
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.12
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
172.24.120.170 (GigabitEthernet2/1/41), from 172.24.120.170, Send flag is 0x0
Composite metric is (5376/2560), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 110 microseconds # This delay is correct (400microsec redist delay + 10microses for link delay1
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.12
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
172.24.120.178 (GigabitEthernet1/1/42), from 172.24.120.178, Send flag is 0x0
Composite metric is (13056/10240), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 410 microseconds
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.13
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
172.24.120.186 (GigabitEthernet2/1/42), from 172.24.120.186, Send flag is 0x0
Composite metric is (13056/10240), route is External
Vector metric:
Minimum bandwidth is 1000000 Kbit
Total delay is 410 microseconds
Reliability is 0/255
Load is 1/255
Minimum MTU is 1
Hop count is 1
External data:
Originating router is 172.26.254.13
AS number of route is 65001
External protocol is BGP, external metric is 0
Administrator tag is 2056 (0x00000B28)
The output is similar for the second two subnets.
The question is why is the subnet 172.23.132.0/24 not being redistributed when 172.23.131.0/24 which matches the same access-list is with the correct metrics? The BGP weight of 32768 for subnet 172.23.131.0/24 is not configured, it's automatically inserted by BGP.
Thanks for taking to time to read this.
