EIGRP LFA SRLG

[Iaroslav]

Is it possible to use SRLG for EIGRP LFA? The documentation mentions SRLG as a tie-breaker but I didn't manage to get the correct behaviour in the lab. I am not sure if I do smth wrong or the feature is just not supported fully yet.

CSR1#sho ip ei topology                        
EIGRP-IPv4 VR(EIGRP) Topology Table for AS(1)/ID(1.1.1.1)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 4.4.4.4/32, 1 successors, FD is 2048000
        via 192.168.13.3 (2048000/1392640), GigabitEthernet2
        via 192.168.12.2 (7946240/1392640), GigabitEthernet1

CSR1#sho run | s router ei
router eigrp EIGRP
 !
 address-family ipv4 unicast autonomous-system 1
  !
  topology base
   fast-reroute per-prefix all
   fast-reroute tie-break srlg-disjoint 1
   fast-reroute load-sharing disable
  exit-af-topology
  network 0.0.0.0
 exit-address-family

CSR1#sho ip route 4.4.4.4 255.255.255.255
Routing entry for 4.4.4.4/32
  Known via "eigrp 1", distance 90, metric 16000, type internal
  Redistributing via eigrp 1
  Last update from 192.168.13.3 on GigabitEthernet2, 00:05:30 ago
  Routing Descriptor Blocks:
  * 192.168.13.3, from 192.168.13.3, 00:05:30 ago, via GigabitEthernet2
      Route metric is 16000, traffic share count is 1
      Total delay is 21 microseconds, minimum bandwidth is 1000000 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 0
      Repair Path: 192.168.12.2, via GigabitEthernet1

!
interface GigabitEthernet1
 srlg gid 1
 ip address 192.168.12.1 255.255.255.0
 delay 10
end
!
interface GigabitEthernet2
 srlg gid 1
 ip address 192.168.13.1 255.255.255.0

[Iaroslav · Accepted solution]

The answer turned out to be simple. SRLG in EIGRP LFA is a tiebreaker, not a constraint. So if there is no alternative besides link in the same SRLG, then the only variant left is used as repair route.