Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.100.0 - Page 583

ACKs 2 (shown in bold) is printed only for ACK packets. The following example shows no change in the updated packets (shown in bold). ACKs 2 (shown in bold) is printed only for ACK packets. 00:10:41 : OSPF(1000:00): Rcv. v:2 t:5(LSAck) l:64 Acks 2 rid:2.2.2.2 aid:1500 chk:0xdbee aut:0 auk: keyid:0 from:Vl 1000 LSType:Type-5 AS External id:160.1.1.0 adv:6.1.0.0 seq:0x8000000c LSType:Type-5 AS External id:160.1.2.0 adv:6.1.0.0 seq:0x8000000c 00:10:41 : OSPF(1000:00): Rcv. v:2 t:5(LSAck) l:64 Acks 2 rid:2.2.2.2 aid:1500 chk:0xdbee aut:0 auk: keyid:0 from:Vl 100 LSType:Type-5 AS External id:160.1.1.0 adv:6.1.0.0 seq:0x8000000c LSType:Type-5 AS External id:160.1.2.0 adv:6.1.0.0 seq:0x8000000c 00:10:41 : OSPF(1000:00): Rcv. v:2 t:4(LSUpd) l:100 rid:6.1.0.0 aid:0 chk:0xccbd aut:0 auk: keyid:0 from:Gi 10/21 Number of LSA:2 LSType:Type-5 AS External(5) Age:1 Seq:0x8000000c id:170.1.1.0 Adv:6.1.0.0 Netmask:255.255.255.0 fwd:0.0.0.0 E2, tos:0 metric:0 LSType:Type-5 AS External(5) Age:1 Seq:0x8000000c id:170.1.2.0 Adv:6.1.0.0 Netmask:255.255.255.0 fwd:0.0.0.0 E2, tos:0 metric:0 To confirm that you enabled RFC-2328-compliant OSPF flooding, use the show ip ospf command. Dell#show ip ospf Routing Process ospf 1 with ID 2.2.2.2 Supports only single TOS (TOS0) routes It is an Autonomous System Boundary Router It is Flooding according to RFC 2328 SPF schedule delay 5 secs, Hold time between two SPFs 10 secs Number of area in this router is 1, normal 0 stub 0 nssa 1 --More-- OSPF ACK Packing The OSPF ACK packing feature bundles multiple LS acknowledgements in a single packet, significantly reducing the number of ACK packets transmitted when the number of LSAs increases. This feature also enhances network utilization and reduces the number of small ACK packets sent to a neighboring router. OSPF ACK packing is enabled by default and non-configurable. Setting OSPF Adjacency with Cisco Routers To establish an OSPF adjacency between Dell Networking and Cisco routers, the hello interval and dead interval must be the same on both routers. In Dell Networking OS, the OSPF dead interval value is, by default, set to 40 seconds, and is independent of the OSPF hello interval. Configuring a hello interval does not change the dead interval in Dell Networking OS. In contrast, the OSPF dead interval on a Cisco router is, by default, four times as long as the hello interval. Changing the hello interval on the Cisco router automatically changes the dead interval. To ensure equal intervals between the routers, use the following command. • Manually set the dead interval of the Dell Networking router to match the Cisco configuration. INTERFACE mode ip ospf dead-interval Examples of Setting and Viewing a Dead Interval In the following example, the dead interval is set at 4x the hello interval (shown in bold). Dell(conf)#int tengigabitethernet 2/2 Dell(conf-if-te-2/2)#ip ospf hello-interval 20 Open Shortest Path First (OSPFv2 and OSPFv3) 583