[ntp:hackers] ntpd send reply to port 123 though client request source port is not 123

Greg Dowd gdowd at symmetricom.com
Fri Oct 18 16:49:23 UTC 2013


I don't believe the code will do that by default.  Is it possible that you have the extreme device configured as a server in YOUR server config?  That would generate requests with destination address 123.  Failing that, perhaps use wireshark to look at the extreme request packet.  Is it a stock mode 3 (client) request?  

-----Original Message-----
From: hackers-bounces+gdowd=symmetricom.com at lists.ntp.org [mailto:hackers-bounces+gdowd=symmetricom.com at lists.ntp.org] On Behalf Of Reeve Yang
Sent: Thursday, October 17, 2013 12:20 PM
To: hackers at lists.ntp.org
Subject: [ntp:hackers] ntpd send reply to port 123 though client request source port is not 123

Hi All,

I'm using ntp-4.2.4p4 as server and found a funny problem in
inter-complying test with extreme switches who run sntp-v1 as client. Those
guys are sending ntp request on non-standard source port, my server
receives the requests and send replies, but it sends with destination port
still as 123. Of course the client side complains not receiving replies!

I'm wondering whether ntp just use fixed port 123 disregarding the received
packets source port? This is a pretty common problem, so before I put any
patch on the source, I'd like to know more information about it. Have you
guys ever experienced the similar problem? How did you fix/work-around it?

Thanks.
- Reeve
_______________________________________________
hackers mailing list
hackers at lists.ntp.org
http://lists.ntp.org/listinfo/hackers


More information about the hackers mailing list