Re: how to troubleshoot "arpresolve: can't allocate llinfo for " errorr ?

From: Rodney W. Grimes <freebsd-rwg_at_gndrsh.dnsmgr.net>
Date: Tue, 13 Feb 2024 17:09:07 UTC
> I get the following error "arpresolve: can't allocate llinfo for 1.1.245.192 on vlan320" I can't explain. (IP edited). I only setup 1.1.245.192/31 between this vlan which parent is a VF from a MLX5EN(4) card .
> 
> I am using a generated mac address and distribute IPs over OSPF  with bird. 
> 
> What could trigger this error? The doc says
> 
> ```
> It "arpresolve: can't allocate llinfo for %d.%d.%d.%d"
> The route for the referenced host points to a device upon which ARP is
> required, but ARP was unable to allocate a routing table entry in which
> to store the host's MAC address.
> This usually points to a misconfigured routing table.

Mis matched netmask on this network segment is a common
cause of this issue.  Check all your hosts that there
netmask matches the /31 you show below.  

I could also be a bad netmask on a route entry,
check your routing table to make sure it has a /31
route or a pair of /32 routes.

> It can also occur if the kernel cannot allocate memory.
> ```
> 
> But I am not sure what to check. Any hint is welcome :)
> 
> The configuration for this vlan is locally:
> 
> ```
> vlan320: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500options=1c680703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG,TXTLS4,TXTLS6>
> ether 02:01:02:01:01:01
> inet 1.1245.193 netmask 0xfffffffe broadcast 255.255.255.255
         ^^^^ not a valid address, so when tiy "obscured" this you also created invalid data.
         I think this was suppose to be 1.1.245.193
 
> inet6 fe80::1:2ff:fe01:101%vlan320 prefixlen 64 scopeid 0x9
> inet6 XXXX:XXXX:1:fe02::2 prefixlen 64
> groups: vlan
> vlan: 320 vlanproto: 802.1q vlanpcp: 0 parent interface: mce1
> media: Ethernet 25GBase-SR <full-duplex,rxpause,txpause>
> status: active
> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> 
> 
> 
> ```
> vlan320: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
> 	options=1c680703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG,TXTLS4,TXTLS6>
> 	ether 02:01:02:02:01:01
> 	inet 1.1.245.192 netmask 0xfffffffe broadcast 255.255.255.255
> 	inet6 fe80::1:2ff:fe02:101%vlan320 prefixlen 64 scopeid 0xa
> 	groups: vlan
> 	vlan: 320 vlanproto: 802.1q vlanpcp: 0 parent interface: mce1
> 	media: Ethernet 25GBase-SR <full-duplex,rxpause,txpause>
> 	status: active
> 	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> ```
> on remote:
> 
> ```
> 
> 
> Beno?t 
> 
> 
> 

-- 
Rod Grimes                                                 rgrimes@freebsd.org