On 13.04.22 09:24, Luca Bertoncello wrote:
Hi list!
I already reported in March my problems using Freeradius over VPN. I spent many time searching the problem, and maybe I found something, but I have no idea how to correct the problem...
So, short explanation: Main office with Freeradius, connected via OpenVPN to our central VPN-Server. Second office with the AccessPoints, connected via OpenVPN to our central VPN. "Normal" pakets from second office to main office (and viceversa) go through both VPNs.
Now, I sniffed the pakets on all servers (VPN server on second office, central VPN server, VPN server on main office and Freeradius), and I discovered that some pakets are blocked.
Wireshark on VPN server of the second office:
12 2022-03-25 14:39:48,154608 10.0.21.10 10.6.21.10 RADIUS 979 Access-Challenge id=86 13 2022-03-25 14:39:48,476555 10.6.21.10 10.0.21.10 IPv4 1500 Fragmented IP protocol (proto=UDP 17, off=0, ID=41c1) 14 2022-03-25 14:39:48,507473 10.0.21.10 10.6.21.10 RADIUS 92 Access-Challenge id=87 15 2022-03-25 14:39:48,533183 10.6.21.10 10.0.21.10 IPv4 1500 Fragmented IP protocol (proto=UDP 17, off=0, ID=41c2) 16 2022-03-25 14:39:51,533406 10.6.21.10 10.0.21.10 IPv4 1500 Fragmented IP protocol (proto=UDP 17, off=0, ID=42d9)
Wireshark on central VPN:
12 2022-03-25 14:39:48,129787 10.0.21.10 10.6.21.10 RADIUS 979 Access-Challenge id=86 13 2022-03-25 14:39:48,488993 10.6.21.10 10.0.21.10 IPv4 1500 Fragmented IP protocol (proto=UDP 17, off=0, ID=41c1) 14 2022-03-25 14:39:48,501213 10.0.21.10 10.6.21.10 RADIUS 92 Access-Challenge id=87
No other pakets after paket 14 (ID 87) reach the central VPN serve, so the problem "must be" either on the central VPN server or on the VPN server oft he second office... Now the very question: do someone have an idea why just the first fragmented paket run over all VPNs and the other one do not?
Thanks a lot Luca - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
Fragmentation if handled different on the path from 10.0.21.10 to 10.6.21.10 than on the way back. Please check firewalls, NAT devices, routers or DDoS appliances including these of your WAN provider. Or setup fragmentation detection within your VPN setup. Mit freundlichen Grüßen, -- [*] sys4 AG https://sys4.de, +49 (89) 30 90 46 64 Schleißheimer Straße 26/MG,80333 München Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 Vorstand: Patrick Ben Koetter, Marc Schiffbauer, Wolfgang Stief Aufsichtsratsvorsitzender: Florian Kirstein