Wireshark reserves: MTU and MSS before use The main part of learning how it works will be able to better understand the operation process. Since Wikipedia specializes in beauty and cannot write better than it, so post its link here: zh./wiki/%E4%BC. MAC frame header definition / / typedef struct _MAC_FRAME_HEADER _attribute_((Packed))UDP_HEADER, *PUDP_HEADER Copy the code Transmission Control Protocol (TCP) When going to school, learn to forget almost, shame ah! Overall packet encapsulation structure I felt curious as if I had discovered a new land, so I hurriedly looked at it and reviewed the relevant protocols. My colleagues in the company were analyzing the problem of slow web page loading, and suddenly used Wireshark. I'm totally confused.Posted on March 23, 2023, 5:17 p.m. How should I fix this? It seems my DNS is totally broken. And if that's not bad enough, I've had to reset my router twice in last week (OpenWRT) because sometimes DNS would break altogether, and Wireshark would show that my local domain, '.lann' was being added to every single query the system made, for example: Is this normal? Is dnsmasq interfering with DNSCrypt-proxy? I tried running dnscrypt without a dns cache, but than I noticed that queries to my localhost and sometimes local network were being forwarded to the nameservers. It even happens for broadcast addresses: 125 37.371037000 localhost localhost DNS 90 Standard query 0x8e53 PTR Įverytime this happens, the queries are followed by a bunch of 'conntecion resets' and other warnings.

13.0.8.10.in-addr.arpa.13.0.8.10.in-addr.arpa.Īnd let's say my VPN server IP is 123.456.78.91, than the queries look like this: 9143 584.912799000 localhost localhost DNS 88 Standard query 0xc198 PTR 19.78.Īnd of course, the answer to these queries are always this: 9144 584.912945000 localhost localhost DNS 88 Standard query response 0xc198 No such name Firstly, after disconnecting from my VPN, with the hypothetical IP address of 10.8.0.13, I see this. When running a dumcap via Wireshark, I've noticed a couple of odd occurrences lately.

I have been using DNSCrypt with dnsmasq on my Ubuntu 14.10 machine.

Ip address wireshark