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My requirement is to create a multiple tap interfaces, each with ip address on same subnet.

I tried this by creating a bridge

               br0 (192.168.1.199)
     ___________|_____________________________________
     |                    |       |      |      |     |
   eth0                  tap0    tap1   tap2   tap3   tap4
                (192.168.1.150)  (.151) (.152) (.153) (.154)

I need all the tap interface be reachable from external PC. When i ping from tap0 to external computer say 192.168.1.200

ping -I tap0 192.168.1.200 -- the ping is not going through. 

But when i ping from 192.168.1.200 to 192.168.1.150 (tap0) it is working, but i get the mac address of the bridge (br0)

I have two problems:

  1. How to ping from tap interface to external
  2. How to get the mac address of the right tap interface, when pinged from outside.
  • Please provide more details (at least which OS you are using) 1. If everything is correctly configured, it could be your firewall, that blocks ping or does not allow forwarding. 2. To get MAC address, use 'arp' command. E.g., 'arp 192.168.1.150' under linux, or 'arp -a' under Windows. – Andrey Sapegin Jun 23 '14 at 7:09
  • My OS is Debian 7.4 and i have tried in ubuntu 13.10 as well. It is not my firewall because arp is not getting resolved for the tap interface, so no packet is going out. What i meant by problem 2 is the packets are received at the receiver with the mac address of the bridge rather than the mac address of the tap. Sorry, for not being clear there. – ramz Jun 23 '14 at 10:05
  • yes , you need some user space program to control tap interface , or remote tunnel whose you tap interface is a part of . – 8zero2.ops Oct 19 '16 at 3:41
1

Re question 1:

ping -I tap0

tells ping to send the ping packet out on tap0. This will bypass the bridge and really only send on the specified "physical" interface. So, effectively, you're not pinging "from" the tap interface, you're pinging "to" it.

If you want to ping "from" the tap interface, you need to attach something to it (e.g. OpenVPN) and send the ping from the other end of the virtual cable the tap interface is connected to.

Re question 2: You could try something like

arp -i br0 -Ds 192.168.1.150 tap0 pub

etc.

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