<pre>
ip4.dst = ip4.src;
ip4.src = <var>S</var>;
-ip4.ttl = 255;
+ip.ttl = 255;
icmp4.type = 0;
next;
</pre>
<p>
ICMP time exceeded. For each router port <var>P</var>, whose IP
address is <var>A</var>, a priority-40 flow with match <code>inport
- == <var>P</var> && ip4.ttl == {0, 1} &&
+ == <var>P</var> && ip.ttl == {0, 1} &&
!ip.later_frag</code> matches packets whose TTL has expired, with the
following actions to send an ICMP time exceeded reply:
</p>
icmp4.code = 0; /* TTL exceeded in transit. */
ip4.dst = ip4.src;
ip4.src = <var>A</var>;
- ip4.ttl = 255;
+ ip.ttl = 255;
next;
};
</pre>
</li>
<li>
- TTL discard. A priority-30 flow with match <code>ip4.ttl == {0,
+ TTL discard. A priority-30 flow with match <code>ip.ttl == {0,
1}</code> and actions <code>drop;</code> drops other packets whose TTL
has expired, that should not receive a ICMP error reply (i.e. fragments
with nonzero offset).
</p>
<pre>
-ip4.ttl--;
+ip.ttl--;
reg0 = <var>G</var>;
next;
</pre>
<p>
- (Ingress table 1 already verified that <code>ip4.ttl--;</code> will
+ (Ingress table 1 already verified that <code>ip.ttl--;</code> will
not yield a TTL exceeded error.)
</p>
icmp4.code = 0; /* Network unreachable. */
ip4.dst = ip4.src;
ip4.src = <var>A</var>;
- ip4.ttl = 255;
+ ip.ttl = 255;
next(2);
};
</pre>