We've talked on this forum in the past about the pros and cons to enabling CTF (Cut-Through Forwarding). Mostly there's nebulous information floating about, where it's suspected that some Tomato features no longer work, but nobody seems to know those features are any more. I think it'd be nice to at least list somewhere -- like in this thread -- definitive stuff in Tomato that stop working or misbehaves when CTF is enabled. Tonight I confirmed one such feature on my RT-AC56U running freshtomato-RT-AC56U-ARM-2018.4-VPN-64K.trx (but was happening with older builds too): upon enabling CTF, the Bandwidth Monitoring feature stops functioning properly. Graphs of real-time traffic, and thus rstats' own knowledge of traffic, "mostly" stops working. I say "mostly" because there does seem to be some degree of traffic that's detected on br0 (LAN), but it's nominal. For example, when doing an Xfinity Speed Test (I use Comcast; my connection is 300/30mbit) with CTF enabled, I see something like 40kbits of traffic under Bandwidth -> Real-Time... while the speed test actually maxes out the connection. And I know this isn't specific to Real-Time/graphing because I enabled CTF about a month and a half ago, and my Monthly data from August is short by about a third, and all of September 2018 reports a total of around 4GBytes. I tend to push around 300-400GBytes/month, guaranteed. I'd have provided this data, but sadly I lost several months (everything from April to September; I found an old backup from March) of rstats data messing about with features and doing firmware upgrades. TL;DR -- Enabling CTF breaks Bandwidth Monitoring in funky ways. If you definitively know of of other features that stop working or act odd, please state them here! I hope this information will be useful for those deciding whether or not to use CTF, as everyone's needs vary.