Keepalived 定期发送免费 ARP

Question

有没有办法让 keepalived 定期发送免费 ARP？

我们遇到了以下情况：

1. 交换机故障（VLAN 设置）
2. keepalived 故障转移到备份实例
3. 备份实例发送了免费 ARP，但 Cisco ASA 设备没有收到它（由于交换机故障）
4. 当交换机恢复时（几分钟后），VIP 无法访问，因为 ASA 未刷新 ARP 表（ARP 表到期时间设置为 4 小时）
5. 由于 ASA 已经拥有来自之前活动节点的 MAC，因此它没有发送 ARP 请求
6. 直到我们重新启动了 keepalived 实例并启动了新的 GARP 后，VIP 才可访问

因此，我们认为我们可以通过定期 GARP 来避免这种情况。这是一种好方法吗？有没有办法在 keepalived 中做到这一点？

还有其他建议可以避免此类问题吗？

Keepalived 配置：

global_defs {
   notification_email {
     [email protected]
   }

   notification_email_from SERVER_1
   smtp_server smtp.server.local
   smtp_connect_timeout 30
   router_id SERVER_1
}

vrrp_instance V1 {
    state BACKUP
    nopreempt
    interface eth0
    lvs_sync_daemon_interface eth0
    virtual_router_id 150
    priority 120
    advert_int 1
    persistence_timeout 0
    smtp_alert

    authentication {
        auth_type PASS
        auth_pass xxx
    }

    virtual_ipaddress {
    10.xxx.xxx.xxx
    }
}

Answer 1

keepalived 1.2.20 及以上版本支持以下关于免费 ARP 的配置设置，vrrp_garp_master_refresh 正是我需要的。

    # delay for second set of gratuitous ARPs after transition to MASTER
    vrrp_garp_master_delay 10    # seconds, default 5, 0 for no second set

    # number of gratuitous ARP messages to send at a time after transition to MASTER
    vrrp_garp_master_repeat 1    # default 5

    # delay for second set of gratuitous ARPs after lower priority advert received when MASTER
    vrrp_garp_lower_prio_delay 10

    # number of gratuitous ARP messages to send at a time after lower priority advert received when MASTER
    vrrp_garp_lower_prio_repeat 1

    # minimum time interval for refreshing gratuitous ARPs while MASTER
    vrrp_garp_master_refresh 60  # secs, default 0 (no refreshing)

    # number of gratuitous ARP messages to send at a time while MASTER
    vrrp_garp_master_refresh_repeat 2 # default 1

    # Delay in ms between gratuitous ARP messages sent on an interface
    vrrp_garp_interval 0.001          # decimal, seconds (resolution usecs). Default 0.

    # Delay in ms between unsolicited NA messages sent on an interface
    vrrp_gna_interval 0.000001        # decimal, seconds (resolution usecs). Default 0.