今回はOSPFのLSAの受信間隔の調整方法について解説します。
座学
LSAの受信間隔の調整
OSPFのLSAは、Link State Type、Link State ID、Advertising Routerの3種類の値で一意に識別されます。この3つの値が等しいLSAは、同じLSAとして認識されます。
OSPFが動作しているルータでは、LSAを受信してから一定期間、同じLSAを受信した場合、破棄します。
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。
LSAの受信間隔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
LSAの受信間隔の変更前
OSPFプロセスの状態確認
R1のLSAの受信間隔が100ミリ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>
LSAの受信間隔の変更後
R1のLSAの受信間隔を500ミリ秒に変更します。
追加した設定
LSAの受信間隔はtimers lsa arrival <milli-second>コマンドで変更可能です。
R1
router ospf 1
timers lsa arrival 500
OSPFプロセスの状態確認
R1のLSAの受信間隔が500ミリ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: 00:08:27.110
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 500 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>
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