Hi, I'm trying to evaluate a new setup with 4 routers. This test setup is on VMs with Jun/7 snapshot.
|--- R2 --- R1 |--- R4 |--- R3 --- See here for better view: https://imgur.com/a/ddyEQPb R2, R3, R4 are on a shared network and do ospf R2, R3 have a static default route to R1 (-priority 50). In final setup it will be with bgp/ibgp but I left it out for simplicity. If R2,R3 connect with R1 on different interfaces (not shared) then I have a network loop of R2->R3 and R3->R2 If I put R1,R2,R3 on the same network I have no loop. info is a bit long but I hope someone has a look. R2# netstat -nr|grep default default 10.200.0.3 UG 0 1409 - 32 vio1 default 10.100.2.0 UGS 0 3 - 50 vio2 R3# netstat -nr|grep default default 10.200.0.2 UG 0 1406 - 32 vio1 default 10.100.3.0 UGS 0 4 - 50 vio3 R4# netstat -nr |grep default default 10.200.0.2 UG 0 4 - 32 vio1 With bgp/ibgp I again have a loop R2,R3 sending to each other R2# netstat -nr | grep default default 10.200.0.3 UG 0 0 - 32 vio1 default 10.100.2.0 UG 0 1 - 48 vio2 R2# bgpctl show ip bgp flags: * = Valid, > = Selected, I = via IBGP, A = Announced, S = Stale origin: i = IGP, e = EGP, ? = Incomplete flags destination gateway lpref med aspath origin *> 0.0.0.0/0 10.100.2.0 130 0 64530 i AI*> 10.200.0.0/16 0.0.0.0 100 0 i R3# netstat -nr | grep default default 10.200.0.2 UG 0 127 - 32 vio1 default 10.200.0.2 UG 0 0 - 48 vio1 R3# bgpctl show ip bgp flags: * = Valid, > = Selected, I = via IBGP, A = Announced, S = Stale origin: i = IGP, e = EGP, ? = Incomplete flags destination gateway lpref med aspath origin I*> 0.0.0.0/0 10.100.2.0 130 0 64530 i * 0.0.0.0/0 10.100.3.0 100 0 64530 i I*> 10.200.0.0/16 10.200.0.2 100 0 i AI* 10.200.0.0/16 0.0.0.0 100 0 i R2 ospfd.conf: router-id 10.200.0.2 metric 1 redistribute default set { metric 1 type 1 } area 0.0.0.0 { interface vio1 { router-priority 2 } interface vio2 { passive } } R3 ospfd.conf: router-id 10.200.0.3 metric 1 redistribute default set { metric 100 type 1 } area 0.0.0.0 { interface vio1 { router-priority 3 } interface vio3 { passive } } # ospfctl show database external Type-5 AS External Link States LS age: 908 Options: -|-|-|-|-|-|-|- LS Type: AS External Link State ID: 0.0.0.0 (External Network Number) Advertising Router: 10.200.0.2 LS Seq Number: 0x80000001 Checksum: 0x18f6 Length: 36 Network Mask: 0.0.0.0 Metric type: 1 Metric: 1 Forwarding Address: 10.100.2.0 External Route Tag: 0 LS age: 908 Options: -|-|-|-|-|-|-|- LS Type: AS External Link State ID: 0.0.0.0 (External Network Number) Advertising Router: 10.200.0.3 LS Seq Number: 0x80000001 Checksum: 0x01a8 Length: 36 Network Mask: 0.0.0.0 Metric type: 1 Metric: 100 Forwarding Address: 10.100.3.0 External Route Tag: 0 # ospfctl show database router Router Link States (Area 0.0.0.0) LS age: 254 Options: -|-|-|-|-|-|E|- LS Type: Router Link State ID: 10.200.0.2 Advertising Router: 10.200.0.2 LS Seq Number: 0x80000002 Checksum: 0xc8b1 Length: 48 Flags: *|*|*|*|*|-|E|- Number of Links: 2 Link connected to: Stub Network Link ID (Network ID): 10.100.2.0 Link Data (Network Mask): 255.255.255.254 Metric: 1 Link connected to: Transit Network Link ID (Designated Router address): 10.200.0.4 Link Data (Router Interface address): 10.200.0.2 Metric: 1 LS age: 254 Options: -|-|-|-|-|-|E|- LS Type: Router Link State ID: 10.200.0.3 Advertising Router: 10.200.0.3 LS Seq Number: 0x80000002 Checksum: 0xdb9a Length: 48 Flags: *|*|*|*|*|-|E|- Number of Links: 2 Link connected to: Stub Network Link ID (Network ID): 10.100.3.0 Link Data (Network Mask): 255.255.255.254 Metric: 1 Link connected to: Transit Network Link ID (Designated Router address): 10.200.0.4 Link Data (Router Interface address): 10.200.0.3 Metric: 1 LS age: 253 Options: -|-|-|-|-|-|E|- LS Type: Router Link State ID: 10.200.0.4 Advertising Router: 10.200.0.4 LS Seq Number: 0x80000002 Checksum: 0xc333 Length: 36 Flags: *|*|*|*|*|-|-|- Number of Links: 1 Link connected to: Transit Network Link ID (Designated Router address): 10.200.0.4 Link Data (Router Interface address): 10.200.0.4 Metric: 1
