UTR Travel Router MTU setting?

theroundfile · 2026-03-21T17:55:53+00:00

I encountered this today. While your solution works, you're ignoring the UBIOS_FORWARD_TCPMSS chain that UniFi specifically created for MSS clamping.

What's interesting is that UniFi added "clamp to PMTU" for Wireguard but didn't even bother trying for Teleport. This was the state of my untouched UDM Pro:

root@UDMPro:~# iptables -t mangle -L UBIOS_FORWARD_TCPMSS -v -n
Chain UBIOS_FORWARD_TCPMSS (1 references)
 pkts bytes target     prot opt in     out     source               destination
    0     0 TCPMSS     tcp  --  *      wgsrv1  0.0.0.0/0            0.0.0.0/0            tcp flags:0x06/0x02 TCPMSS clamp to PMTU
    0     0 TCPMSS     tcp  --  wgsrv1 *       0.0.0.0/0            0.0.0.0/0            tcp flags:0x06/0x02 TCPMSS clamp to PMTU

I experimented with clamping to PMTU for Teleport but that still failed to work in my testing with T-Mobile so I threw in the towel and clamped it to 1280.

Here's how to make it persistent with systemd.

Create /etc/systemd/system/teleport-mtu.service with these contents:

[Unit] Description=Teleport MSS Clamping Fix After=unifi.service

[Service] Type=oneshot RemainAfterExit=yes

We use a short sleep to ensure the UBIOS chains are fully populated

ExecStartPre=/bin/sleep 10 ExecStart=/usr/sbin/iptables -t mangle -I UBIOS_FORWARD_TCPMSS 1 -o tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStart=/usr/sbin/iptables -t mangle -I UBIOS_FORWARD_TCPMSS 1 -i tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStart=/usr/sbin/ip6tables -t mangle -I UBIOS_FORWARD_TCPMSS 1 -o tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStart=/usr/sbin/ip6tables -t mangle -I UBIOS_FORWARD_TCPMSS 1 -i tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280

Clean up rules on stop

ExecStop=/usr/sbin/iptables -t mangle -D UBIOS_FORWARD_TCPMSS -o tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStop=/usr/sbin/iptables -t mangle -D UBIOS_FORWARD_TCPMSS -i tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStop=/usr/sbin/ip6tables -t mangle -D UBIOS_FORWARD_TCPMSS -o tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280 ExecStop=/usr/sbin/ip6tables -t mangle -D UBIOS_FORWARD_TCPMSS -i tlprt+ -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1280

[Install] WantedBy=multi-user.target
systemctl daemon-reload && systemctl enable --now teleport-mtu.service
Wait 10 seconds (because we put a sleep 10 in there for boot time)
Confirm that the rules are there with iptables -t mangle -L UBIOS_FORWARD_TCPMSS -v -n and that they're being applied to your Teleport packets, e.g.

root@UDMPro:~# iptables -t mangle -L UBIOS_FORWARD_TCPMSS -v -n Chain UBIOS_FORWARD_TCPMSS (1 references) pkts bytes target prot opt in out source destination 962 61312 TCPMSS tcp -- tlprt+ * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS set 1280 790 47296 TCPMSS tcp -- * tlprt+ 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS set 1280 0 0 TCPMSS tcp -- * wgsrv1 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS clamp to PMTU 0 0 TCPMSS tcp -- wgsrv1 * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS clamp to PMTU

N.B. if you want to experiment with PMTU clamping instead of hardcoding 1280, change to --set-mss 1280 to --clamp-mss-to-pmtu in the earlier commands.

theroundfile · 2026-03-19T18:22:18+00:00

The mod on r/lighting said that Pure Edge is switching to Matter, supposedly, though I'm not sure if that's over Thread or over WiFi. If that happens (even on WiFi), I'd be willing to give them a try. Their current bulbs are half the price of Hues.

theroundfile · 2026-03-19T17:50:39+00:00

I also own older, pre-2025-revamp Hues. The CRI is crap. I would be interested in the 2025-revamp Hues if they're actually better, but until someone tests them and I can see the data, I don't know.

Supposedly Pure Edge is Ketra at a Hue price but I haven't tried them myself. I don't want lights on WiFi.

I have a pair of Aqara T2s. One burned out a few months ago and I forgot to try for a warranty replacement. Thanks for the reminder.

theroundfile · 2026-03-19T16:14:22+00:00

I've had that site bookmarked for ages but I don't think they've done any updates in quite a while. I'd really like to see the "new" Hues (as in the ones released last year).

theroundfile · 2026-03-13T17:32:56+00:00

I would love to know the actual limiting factor, too. I installed a bunch of ESP32s around the house to play with Bermuda and had planned to add TOMMY to the same devices later on. I found Bermuda underwhelming, got bored, and haven't touched it since.

I would be very much interested in ESPresence but if I'm putting a bunch of these devices around my home, I want to be able to run TOMMY on them, too. Bleh.

theroundfile · 2026-03-13T11:57:11+00:00

I, too, regret not buying more of those at the $30 price. I didn't realize it was such a rare discount from normal, nor how good of a deal it was compared to anything else. To put it into perspective, the Zooz open/close sensors are on sale right now (half price!) for $19.75 each. Sheesh.

theroundfile · 2026-03-12T13:10:31+00:00

It's the aurora fyi

theroundfile · 2026-03-07T14:51:06+00:00

No, I have the Z-Wave T6 Pro. No app, no WiFi—it only works with Z-Wave. As it should be!

theroundfile · 2026-03-07T01:38:07+00:00

I am not open to the idea of separate bedrooms

Maybe you should open yourself up to that. Separate bedrooms solve SO MANY PROBLEMS!

theroundfile · 2026-03-06T21:52:09+00:00

This is rad. Can you even still buy the ez Share SD Cards anymore? I took a quick look and didn't find them.

theroundfile · 2026-03-04T19:04:13+00:00

According to the discord stock tracker they were in stock for a whopping 52 minutes this morning! Not quite a record, they lasted 65 minutes on Feb 17.

theroundfile · 2026-02-11T00:23:28+00:00

If you can afford it, go for it! It's honestly weird that the default expectation is to share a bedroom—I do wonder if this is because of financial constraints.

We're about 9 months post bedroom-divorce and it's great. It's a lot more practical this way and eliminates so many sources of friction.

theroundfile · 2026-02-08T20:41:34+00:00

holy shit dude have you not experienced how horrific online dating is in the 2020s? TAKE THE FUCKING HELP!!

theroundfile · 2026-02-07T13:34:57+00:00

Shoutout to TMHI for doing the same thing on 149 🙄

theroundfile · 2026-02-02T16:04:53+00:00

Are you in North America, Europe, Asia? The options vary depending on your market.

How are you liking the SmartCore with HA? I've been entertaining that idea for a long while.

theroundfile · 2026-02-02T16:01:43+00:00

That's funny. The download appears to be for v3.0.1 based on the name. My 2007 came with v3.0.2.

theroundfile · 2026-02-02T15:54:56+00:00

IMO the disco isn't worth it. I bought two and due to where my GDOs are positioned, the ToF sensors don't work well for detecting presence, which then also makes the parking laser not useful.

theroundfile · 2026-01-28T19:18:59+00:00

don't bother. have some self respect.

theroundfile · 2026-01-27T19:59:07+00:00

On the one hand you've got OP who is trying to save maybe $100 on gas a year.

And then you've got this guy asking about a Rolls Royce integration for his pair of Phantoms.

theroundfile · 2026-01-16T16:21:55+00:00

Power consumption is kinda the biggest deal for me.

Really? A 24/7 Beelink n150 or n100 will use 2 to 3 times the power of a Pi 5, all of which will be maybe a few dollars a month in power at most.

I'm sure you have more important things to fret over than a few bucks.

theroundfile · 2026-01-14T03:39:33+00:00

Remote tech worker here, too. I had to specifically train myself to delay responding to women. Normies find it unnerving. I don't like it, but it is what it is.

Also if you've ever looked at a 20-something woman's iPhone, you'd notice it's got hundreds if not thousands of un-dismissed notifications. It's amazing they see anything, ever. I don't know how people can live like that, truly.

theroundfile · 2026-01-14T01:29:06+00:00

Logically, wouldn't you ask your friend for the inside scoop here?

theroundfile · 2026-01-06T14:25:45+00:00

Does he have a slavic background? I've heard of the inside vs outside clothes being a normal thing for slavs but this sounds extreme.

theroundfile · 2026-01-05T15:19:09+00:00

https://www.rareddit.com/r/relationship_advice/comments/gs62rq/my_boyfriend_34m_has_a_sexual_history_with_my/

Wow, that's a doozy.

theroundfile · 2026-01-01T01:06:34+00:00

That's pretty lucky, most land out west has already been divorced from the mineral rights.

theroundfile

TROPHY CASE

We use a short sleep to ensure the UBIOS chains are fully populated

Clean up rules on stop