今回はOSPFのGroup Packet Pacing Timerについて解説します。
この記事の目次
座学
Group Packet Pacing Timer
以前の記事で、OSPFが動作しているルータは自身が生成したLSAのLink State Ageが1800秒を超えた場合、LSAを再生成し、ネイバーに広報し、ネイバーのLSDBに存在しているLSAのLink State Ageを0秒にリフレッシュします。
この際、ルータはLSA毎に個別にLink State Ageを確認するのではなく、一定間隔でLSDB内の全LSAのLink State Ageを確認し、Link State Ageが1800秒を超えているLSAは一括でリフレッシュします。この確認間隔のことをGroup Packet Pacing Timerと呼びます。
実機での動作確認
検証内容
R1のg2、R2のg2でOSPF Area 0を有効にします。
Network TypeにはPoint-to-Pointを使用します。
Group Packet Pacing Timerのパラメータを確認します。
初期設定
interface GigabitEthernet2
ip address 10.1.1.1 255.255.255.0
ip ospf network point-to-point
!
router ospf 1
router-id 1.1.1.1
network 10.1.1.0 0.0.0.255 area 0
interface GigabitEthernet2
ip address 10.1.1.2 255.255.255.0
ip ospf network point-to-point
!
router ospf 1
router-id 2.2.2.2
network 10.1.1.0 0.0.0.255 area 0
Group Packet Pacing Timerの変更前
OSPFプロセスの状態確認
R1のGroup Packet Pacing Timerが240秒であることが確認できます。
R1
R1#show ip ospf
Routing Process "ospf 1" with ID 1.1.1.1
Start time: 2w1d, Time elapsed: 00:07:51.340
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Supports NSSA (compatible with RFC 3101)
Supports Database Exchange Summary List Optimization (RFC 5243)
Event-log enabled, Maximum number of events: 1000, Mode: cyclic
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 50 msecs
Minimum hold time between two consecutive SPFs 200 msecs
Maximum wait time between two consecutive SPFs 5000 msecs
Incremental-SPF disabled
Initial LSA throttle delay 50 msecs
Minimum hold time for LSA throttle 200 msecs
Maximum wait time for LSA throttle 5000 msecs
Minimum LSA arrival 100 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
EXCHANGE/LOADING adjacency limit: initial 300, process maximum 300
.
<一部省略>
Group Packet Pacing Timerの変更後
R1のGroup Packet Pacing Timerを500秒に変更します。
追加した設定
Group Packet Pacing Timerはtimers pacing lsa-group <second>コマンドで変更可能です。
R1
router ospf 1
timers pacing lsa-group 500
OSPFプロセスの状態確認
R1のGroup Packet Pacing Timerが500秒に変化したことが確認できます。
R1
R1#show ip ospf
Routing Process "ospf 1" with ID 1.1.1.1
Start time: 2w1d, Time elapsed: 00:16:02.268
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Supports NSSA (compatible with RFC 3101)
Supports Database Exchange Summary List Optimization (RFC 5243)
Event-log enabled, Maximum number of events: 1000, Mode: cyclic
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 50 msecs
Minimum hold time between two consecutive SPFs 200 msecs
Maximum wait time between two consecutive SPFs 5000 msecs
Incremental-SPF disabled
Initial LSA throttle delay 50 msecs
Minimum hold time for LSA throttle 200 msecs
Maximum wait time for LSA throttle 5000 msecs
Minimum LSA arrival 100 msecs
LSA group pacing timer 500 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
EXCHANGE/LOADING adjacency limit: initial 300, process maximum 300
.
<一部省略>
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