On Sat, Oct 7, 2023 at 1:38 AM <to...@tuxteam.de> wrote: > > On Fri, Oct 06, 2023 at 05:20:22PM -0400, Jeffrey Walton wrote: > > On Fri, Oct 6, 2023 at 2:04 PM Balaji G <gbalaji...@gmail.com> wrote: > > > > > > Hi, > > > I am using "Debian GNU/Linux 11 (bullseye)" with kernel version > > > 5.16.12. > > > When i do a link up/down i don't see any Gratuitous ARP being sent. > > > > > > # echo 1 > /proc/sys/net/ipv4/conf/eno5np0/arp_notify > > > # ip link set down dev eno5np0 > > > # ip link set up dev eno5np0 > > > > > > Captured all the packets via tcpdump & the tcpdump is not showing any > > > Gratuitous ARP packets. > > > > > > But, with the same commands i could see the Gratuitous ARP being sent in > > > Red hat.9.0 (Plow). > > > So, please let me know if this is a specific scenario in Debian 11 ?? > > > > I think that's now Poettering: > > https://github.com/systemd/systemd/blob/main/src/libsystemd-network/sd-ipv4acd.c#L302 > > As Geert says, probably it needs an ip address to be able to send > an ARP. Perhaps the Redhat box has one set by default?
OP asked if this was specific to Red Hat. The answer is No, it is baked into Systemd nowadays. > What does "ip addr show dev xxxx" say? I have no idea. Jeff