I installed a L2TP IPsec VPN over a Unifi USG for a client of mine.
Everything works like a charm, expect one user, that tries to connect with a MacStudio. He permanently gets disconnected after he fires a request to the NAS in the VPN.
That behaviour started some weeks ago after he tried to download a large video file about 8Gbs.
Here is the ppp.log for the connection:
Mon Nov 21 16:13:35 2022 : publish_entry SCDSet() failed: Success!
Mon Nov 21 16:13:35 2022 : publish_entry SCDSet() failed: Success!
Mon Nov 21 16:13:35 2022 : l2tp_get_router_address
Mon Nov 21 16:13:35 2022 : l2tp_get_router_address 172.20.XXX.XXX from dict 1
Mon Nov 21 16:13:35 2022 : L2TP connecting to server '37.24.XXX.XXX' (37.24.XXX.XXX)...
Mon Nov 21 16:13:35 2022 : IPSec connection started
Mon Nov 21 16:13:35 2022 : IPSec phase 1 client started
Mon Nov 21 16:13:35 2022 : IPSec phase 1 server replied
Mon Nov 21 16:13:37 2022 : IPSec phase 2 started
Mon Nov 21 16:13:37 2022 : IPSec phase 2 established
Mon Nov 21 16:13:37 2022 : IPSec connection established
Mon Nov 21 16:13:37 2022 : L2TP sent SCCRQ
Mon Nov 21 16:13:38 2022 : L2TP received SCCRP
Mon Nov 21 16:13:38 2022 : L2TP sent SCCCN
Mon Nov 21 16:13:38 2022 : L2TP sent ICRQ
Mon Nov 21 16:13:38 2022 : L2TP received ICRP
Mon Nov 21 16:13:38 2022 : L2TP sent ICCN
Mon Nov 21 16:13:38 2022 : L2TP connection established.
Mon Nov 21 16:13:38 2022 : L2TP set port-mapping for en1, interface: 17, protocol: 0, privatePort: 0
Mon Nov 21 16:13:38 2022 : using link 0
Mon Nov 21 16:13:38 2022 : Using interface ppp0
Mon Nov 21 16:13:38 2022 : Connect: ppp0 <--> socket[34:18]
Mon Nov 21 16:13:38 2022 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x66a7093> <pcomp> <accomp>]
Mon Nov 21 16:13:38 2022 : rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth eap> <magic 0xa572b004>]
Mon Nov 21 16:13:38 2022 : lcp_reqci: returning CONFNAK.
Mon Nov 21 16:13:38 2022 : sent [LCP ConfNak id=0x1 <auth chap MS-v2>]
Mon Nov 21 16:13:38 2022 : rcvd [LCP ConfReq id=0x2 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa572b004>]
Mon Nov 21 16:13:38 2022 : lcp_reqci: returning CONFACK.
Mon Nov 21 16:13:38 2022 : sent [LCP ConfAck id=0x2 <asyncmap 0x0> <auth chap MS-v2> <magic 0xa572b004>]
Mon Nov 21 16:13:41 2022 : sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x66a7093> <pcomp> <accomp>]
Mon Nov 21 16:13:41 2022 : rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x66a7093> <pcomp> <accomp>]
Mon Nov 21 16:13:41 2022 : sent [LCP EchoReq id=0x0 magic=0x66a7093]
Mon Nov 21 16:13:41 2022 : rcvd [CHAP Challenge id=0x80 <8560c3e3d9220709414b7ab20b1ad4XX>, name = "xl2tpd"]
Mon Nov 21 16:13:41 2022 : sent [CHAP Response id=0x80 <3f8d9d242462f8b7b1ab2c2b6521bc2d00000000000000001eb445e1bdbc2c8a4d42a286533ff318dc82cXX$
Mon Nov 21 16:13:41 2022 : rcvd [LCP EchoRep id=0x0 magic=0xa572b004]
Mon Nov 21 16:13:41 2022 : rcvd [CHAP Success id=0x80 "S=444EAF8C0498C45397E7D58759DBC96266CE65XX"]
Mon Nov 21 16:13:41 2022 : sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
Mon Nov 21 16:13:41 2022 : sent [IPV6CP ConfReq id=0x1 <addr fe80::9e76:0eff:XXXX:XXXX>]
Mon Nov 21 16:13:41 2022 : rcvd [IPCP ConfReq id=0x1 <addr 10.255.255.0>]
Mon Nov 21 16:13:41 2022 : ipcp: returning Configure-ACK
Mon Nov 21 16:13:41 2022 : sent [IPCP ConfAck id=0x1 <addr 10.255.255.0>]
Mon Nov 21 16:13:41 2022 : rcvd [IPCP ConfNak id=0x1 <addr 10.1.1.1> <ms-dns1 10.11.15.1> <ms-dns3 10.11.15.1>]
Mon Nov 21 16:13:41 2022 : sent [IPCP ConfReq id=0x2 <addr 10.1.1.1> <ms-dns1 10.11.15.1> <ms-dns3 10.11.15.1>]
Mon Nov 21 16:13:41 2022 : rcvd [LCP ProtRej id=0x3 80 57 01 01 00 0e 01 0a 9e 76 0e ff fe 3a 79 9f]
Mon Nov 21 16:13:41 2022 : rcvd [IPCP ConfAck id=0x2 <addr 10.1.1.1> <ms-dns1 10.11.15.1> <ms-dns3 10.11.15.1>]
Mon Nov 21 16:13:41 2022 : ipcp: up
Mon Nov 21 16:13:41 2022 : local IP address 10.1.1.1
Mon Nov 21 16:13:41 2022 : remote IP address 10.255.255.0
Mon Nov 21 16:13:41 2022 : primary DNS address 10.11.15.1
Mon Nov 21 16:13:41 2022 : secondary DNS address 10.11.15.1
Mon Nov 21 16:13:41 2022 : Received protocol dictionaries
Mon Nov 21 16:13:41 2022 : l2tp_wait_input: Address added. previous interface setting (name: en1, address: 172.20.XXX.XXX), current interface sett$
Mon Nov 21 16:13:41 2022 : Committed PPP store on install command
Mon Nov 21 16:13:45 2022 : L2TP port-mapping update for en1 ignored: VPN is the Primary interface. Public Address: 0, Protocol: None, Private P$
Mon Nov 21 16:13:45 2022 : L2TP clearing port-mapping for en1
Mon Nov 21 16:15:09 2022 : L2TP received StopCCN
Mon Nov 21 16:15:09 2022 : L2TP hangup
Mon Nov 21 16:15:09 2022 : ipcp: down
Mon Nov 21 16:15:09 2022 : Connection terminated.
Mon Nov 21 16:15:09 2022 : L2TP clearing port-mapping for en1
Mon Nov 21 16:15:09 2022 : Connect time 1.6 minutes.
Mon Nov 21 16:15:09 2022 : Sent 109022 bytes, received 152039 bytes.
Mon Nov 21 16:15:09 2022 : L2TP disconnecting...
Mon Nov 21 16:15:09 2022 : L2TP sent CDN
Mon Nov 21 16:15:09 2022 : L2TP sent StopCCN
Mon Nov 21 16:15:09 2022 : L2TP disconnected
The VPN worked for some weeks, than stopped working after the file download. Before that, he already had some connection drops, but could successfully reconnect. He's connected via 4G modem, I also tried another carrier, same result.
Can you help me please fixing this problem?
I already tried to recreate the VPN, tried another internet network and rebooting.
The connection stays stable until he tries to connect to another network client...
Greetings from Germany and thanks to you all!
Sacrifyser
