As wise monks have already stated above:
- arp only works for IP address from your local (segment|subnet|broadcast domain)
- if you try to arp-resolve an IP address from a different subnet, the resulting MAC address will be that of the router interface nearest you.
- MAC addresses are an Ethernet (not PPP) thang
Token-Ring and FDDI devices also have MAC addresses but, IIRC, you get into (big|little)-endian stuff there.
Arcnet and Appletalk used their own funkomatic hardware addressing schemes.
If you are indeed looking for the MAC address of a local-to-your-LAN-segment device, (code) MAC n' IP cheese includes code of OWTDI.
cheers,
Don
bumbling toward Perl Adept
(it's pronounced "why-bick")
Update: I was thinking of IPv4 only.
As lhoward points out, IPv6 is substantially different.
Update 2: Working from riffraff's Re: Re: Re: How can I find a MAC address from aremote IP ? post above, I found that (code) MAC n' IP cheese can work for remote segments just by replacing the "Querying ARP table..." section with
snmpwalk <router_name_or_address> <community_string> IpnetToMediaPhysAddress
Woo-hoo! 8^)
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|