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Two TTL values seen when using ip.ttl

asked 2025-06-09 15:04:41 +0000

gielo gravatar image

When using ip.ttl filter, I sometimes get two values for example 128,123. What does that mean?

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Is the traffic encapsulated, e.g. IP over something over IP?

grahamb gravatar imagegrahamb ( 2025-06-09 15:28:40 +0000 )edit

Also occurs in ICMP packets that include the IP header of the offending outbound packet.
The Ultimate PCAPfrom https://weberblog.net/the-ultimate-pcap/ includes both encapsulated and ICMP packets that match a display filter of count(ip.ttl) > 1.

Chuckc gravatar imageChuckc ( 2025-06-09 19:42:55 +0000 )edit

Do you mean in one packet or in two packets?

Christian_R gravatar imageChristian_R ( 2025-06-11 05:28:30 +0000 )edit

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answered 2025-07-14 20:36:09 +0000

André gravatar image

In general, if a field is found multiple times in a packet, it is displayed as a list. The same applies when added as a column in Wireshark. For example:

 tshark -r file.pcapng -T fields -e ip.addr -Y ip

Will normally show 2 IP4-addresses (src + dst) as a comma-seperated list. Comma is the default, that can be changed with the option -E aggregator.

So if ip.ttl outputs multiple values it occurs multiple times. for example a ICMP packet.

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Asked: 2025-06-09 15:04:41 +0000

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Last updated: Jul 14