I currently have a BTHub5-3CMJ (ISP router) setup as a "modem" due to the fact that my internet is on a VDSL and not ADSL connection (i.e. I can't just use any old modem) and also because I am wanting to save money. To that I have hooked a Linksys 1900acs v1. Using just the ISP router as a router, I get my normal 50mbps down, 10mbps up. I then disable dhcp (tried this with dhcp on as well btw) and wifi etc on the BTHub and hook up the Linksys as the sole device using a static ip. I then setup wifi on the linksys leaving all other settings at stock (I have tried this with and without upgrading packages through opkg). It works fine for 3-4 days, but then on the "modem" I start getting this error (at very close intervals):
OUT: BLOCK [7] ICMP replay (ICMP type 3 code 1(or 3 sometimes) "router ip"->"dest. ip" on ppp3)
This also happens to somehow throttle down my internet to the barely usable speeds of <1mbps down and <0.5mbps up.
I gathered that this probably has something to do with the firewall on the BTHub, so I "disable" that. I put disable into quote marks as that literally did nothing at all. I then proceed to move the router into dmz on the BTHub. Still no change.
I then googled the issue, and it seems to be a long-running problem with BTHub5's however I have yet to find a solution that works for me.
In LEDE itself (after enabling logging dropped packets), I see this error pop up literally every second:
Sat Oct 14 15:24:50 2017 kern.warn kernel: [16444.671848] MSSFIX(wan): IN=br-lan OUT=eth1 MAC="mac address" SRC="src_ip" DST="dst_ip" LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=34077 DF PROTO=TCP SPT=42981 DPT=8080 WINDOW=13600 RES=0x00 SYN URGP=0
So I'm coming here to ask if there is anything that I could try inside LEDE to try to fix this, just to work out whether LEDE isn't properly configured or whether the BTHub is at fault and I should get an actual modem as I don't want to cash out money just to find out that it has fixed nothing.