Missing ARP Reply

when using tcpdump over my dsl interface I can see ARP requests looking for Gateway MAC Address but I can't get reply

23:30:30.554185 c8:77:65:10:60:d0 (oui Unknown) > Broadcast, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has tell, length 28

Meanwhile, I'm ping from outside and I can see the ICMP packets incoming, so I think the gateway is up and running

23:30:32.182165 84:c1:c1:7d:46:9b (oui Unknown) > c8:77:65:10:60:d5 (oui Unknown), ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 125, id 7255, offset 0, flags [none], proto ICMP (1), length 60) > ICMP echo request, id 1, seq 257, length 40

Any suggestions ?

Do you have some problem from the missing arp or you just think that something is wrong?
FYI arp is not a protocol used in dsl.

I can't ping the gateway so I started dump network traffic

And you sure it's pingable? Unfortunately, lots of Internet nodes reject ICMP.

Do you mean your regular Ethernet interface that is connected to your DSL modem or something else?

Yes, using the original provider's router it is pingable

1 Like

I'm using tcpdump -i dsl0, this is the DSL interface of my router

This is the configuration

config dsl 'dsl'
        option tone 'av'
        option xfer_mode 'ptm'
        option line_mode 'vdsl'
        option ds_snr_offset '0'
        option firmware '/lib/firmware/lantiq-vrx200-b.bin'
        option annex 'b'
        option vid '835'
        option type '8021q'

config interface 'wan'
        option proto 'static'
        option gateway'
        list ipaddr ''
        option device 'dsl0.835'

config device
        option type '8021q'
        option ifname 'dsl0'
        option vid '835'
        option name 'dsl0.835'
        option mtu '1500'
        option macaddr 'C8:77:65:10:60:D0'
        option ipv6 '0'

My provider is using VLAN 835