Re: UDP Broadcast traffic?

There are two MAC addresses listed in the trace, shown below. The source is
the address of the Allen-Bradley PLC. The second I don't recognize and
don't know how to track down.
Joe

Frame 2 (202 bytes on wire, 202 bytes captured)

Ethernet II, Src: Allen-Br_2b:0d:9a (00:00:bc:2b:0d:9a), Dst:
01:00:5e:40:02:40 (01:00:5e:40:02:40)

Internet Protocol, Src: 192.168.11.10 (192.168.11.10), Dst: 239.192.2.64
(239.192.2.64)

User Datagram Protocol, Src Port: 2222 (2222), Dst Port: 2222 (2222)

EtherNet/IP (Industrial Protocol)

<briggs@xxxxxxxxxxxxxxxxx> wrote in message
news:dP+jVmzcqHRi@xxxxxxxxxxxxxxxxxxxxxxxxxxx
In article <ltiyi.6546$4w7.1359@xxxxxxxxxxxxxxxxxxxxxxxxxx>, "Joe"
<jwduehmig@xxxxxxxxx> writes:
Well, I ran Merv's commands with no change in behavior. My only other
thought is that there may be another connection between the two networks.
But without a router, not sure how the traffic would bridge the two
subnets.
Any thoughts on this?

Look at the source MAC address on the Ethereal trace taken on the
destination side of the router.

If it's the router's MAC address then the traffic is coming from
the router.

If it's somebody else's MAC address then the traffic is coming from
somewhere else.

If the two networks have a layer 2 connection between them in addition
to the layer 3 routed path then this would be consistent with your
symptoms.


.

Relevant Pages

  • Re: Block MAC-Address on a 2851 Router?
    ... Yes, you can block a MAC on a Router using ACL's, however there are ... Router and not a Layer 3 Switch, where the method is likely to be ... A MAC is a Layer 2 construction, so while you can build a MAC ACL ... drop the interface down to Layer 2 by putting that PORT into BRIDGE ...
    (comp.dcom.sys.cisco)
  • Re: Sky Broadband + Linux
    ... The remote device must know the MAC address or it wouldn't be able to send the layer 3 traffic to the right place. ... What you/Whiskers may be thinking of, IIRC is that some isp uses the MAC of their preconfigured router or something derived from it, as your ppp logon user name. ...
    (uk.comp.os.linux)
  • Re: Email issue
    ... you will have trace of your mail stravelling in your system and you will be ... MCSE Windows 2000, MCSA Messaging, CCEA, RSA SecureID CSE ... > The senerio is as follows both users use a mac and pc. ...
    (microsoft.public.exchange2000.general)
  • Re: Can You Explain This iptables Rule?
    ... > Is it possible to specify computer As MAC in an iptables rule even ... > though a router is in between A and B? ... MAC (layer 2) addresses are only visible on local networks. ...
    (comp.os.linux.security)
  • Re: OT:Why Do Wireless Routers Ship With Security Switched Off?
    ... I would love to trace who the people were who decided that my ... inadvertently open connection was worth using. ... I still have their MAC ...
    (uk.media.dvd)