Hi,
We are faced with a strange ARP table issue in Mikrotik (doesn’t seem to be RB model-specific). I have written a script that i put in my schedule to run every minute on 20+ Mikrotik routers. Script is simple… Get all arp entries, separate values with comma and send to syslog server then parse to mySQL. All works as intended except 1 thing… At some random point some devices that are connected to this network via wired or wireless (different subnets), are seen in ARP table with their external (GPRS) IP address. This is beyond me, since no interface on the router has an IP out of this IP range. It seems that all affected client devices are Samsung mobile phones?! with Android system. Also posting a script example:
:local arpip;
:local arpmac;
:local arpinterface;
:local arpinvalid;
:local arpdhcp;
:local arpdynamic;
:local arpdisabled;
:foreach binding in=[
/ip arp find] do={:set arpip [/ip arp get $binding address];
:set arpmac [/ip arp get $binding mac-address];
:set arpinterface [/ip arp get $binding interface];
:set arpinvalid [/ip arp get $binding invalid];
:set arpdhcp [/ip arp get $binding DHCP];
:set arpdynamic [/ip arp get $binding dynamic];
:set arpdisabled [/ip arp get $binding disabled];
:log info (“,” . $arpip . “,” . $arpmac . “,” . $arpinterface . “,” . $arpinvalid . “,” . $arpdhcp . “,” . $arpdynamic . “,” . arpdisabled . “,ARP”)
};
Anybody has any idea why external IP addresses are seen in ARP with internal MAC addresses for these devices?
e.g.:
IP MAC INTERFACE
188.196.72.147 98:0C:82:25:9A:A1 WLAN-bridge
tnx for any info!
br
bysaRD