AltostratusHi! I will do an RMA, replacing one BigIP standalone box with a new one.
Is there any way to force BigIP to send gratuitous ARP for all the IP (VS, SelfIP) it has configured, so I will not need to clear the ARP caches of external devices?
Thanks!
CumulonimbusYou might want to consider configuring MAC masquerade for your services to minimize outage. See: sol13502: Configuring MAC masquerade (11.x) https://support.f5.com/kb/en-us/solutions/public/13000/500/sol13502.html .
Or, would run "tmsh load sys config" force gratuitous arp sending? A question, not an answer, though.
AltostratusHi! I did a simple lab, here my conclusions:
Doing a "tmsh load sys config" doesn't force gratuitous arp
Configuring MAC masquerade in a standalone box (in the default traffic group) doesn't change the MAC Address, nor force a gratuitous arp
Do a a "Force Offline" and then a "Release Offline" don't force gratuitous arp
Reboot the F5 doesn't force gratuitous arp (that was a surprise for me)
As a workaround, I'm seeing the arping tool is installed, but I tried "arping -q -c 1 -A self_ip" and it sent to all the configured vlans a gratuitous arp with the MAC of the Management port (so it's not useful), and "arping -q -c 1 -I vlan1 -A self_ip" didn't work
Does anybody have any other idea?
CumulonimbusWell, in that case, you can always try to ping the VIP address from another device. :-)
I find it hard to believe there is no ga after a reboot.
CumulonimbusI have run into this problem myself after an upgrade to 11.6.2HF2. It turns out that the MAC address changed after the upgrade, and the connecting switch has the old one. But why does it change?
Answer from TAC:
They confirmed that MAC address is dynamically allocated and is not guaranteed to persist across reboots/upgrades.Solution: https://support.f5.com/csp/article/K15858.
NimbostratusI found another articule (https://support.f5.com/csp/article/K19910045), I ran it and it works!
When I ran this procedure, I ran tcpdump too at a linux server, and this was the result.
f6:15:63:56:b3:04 > ff:ff:ff:ff:ff:ff, ARP, length 60: Request who-has 10.0.141.254 (ff:ff:ff:ff:ff:ff) tell 10.0.41.252, length 46 f8:15:63:56:6b:0a > ff:ff:ff:ff:ff:ff, ARP, length 60: Request who-has 10.0.141.1 (ff:ff:ff:ff:ff:ff) tell 10.0.41.1, length 46
Those are packets of Gratuitus ARP from F5 LTM.
GARP will be generated if 1. status of any vip changes 2. box become active 3. status of any self-ip changes
GARP will not be sent for VIPs if IP of the VIP does not belong to subnets of any self-ip
AltostratusHi! Have you tried this procedure in a Standalone box? https://support.f5.com/csp/article/K19910045
Thanks!
