I have Charter Internet service and I had some strange things going on from late last night until about noon or so today.
Basically, the symptom was miserable browsing. By miserable, I mean it would take minutes for pages to load, if they loaded at all. What was a little confusing at first was that I had just installed apt-cacher-ng to reduce bandwidth to the debian mirrors and the timing was such that I initially thought it(apt-cacher-ng) was causing problems. I was able to determine thereafter that apt-cacher-ng had nothing to do with what was going on. I basically left it last night, after poking around looking for anything suspicious on the network. All the local networking was fine (ssh, samba, etc). It was only going out on the net where I had problems.
This morning, I called Charter to see if there had been any maintenance or known outages. There were none. The problem persisted, so I started working it from individual computers back to the modem. Eventually, after going through all the equipment, I was left with my EEE wired to the modem downstairs and the problem was still there. I left it at that point, due to other obligations. Upon returning later (around 11 or so) I once again fired up the EEE with the modem. The EEE didn’t even get an IP this time, so I powr-cycled the modem, and everything started working again. The only change I could note was the IP assigned by Charter. I started bringing everything back up and the problem was gone. Email, browsing and net access in general were all back to normal.
I’ll also note that, while the net access problem was ongoing, I power-cycled the modem a number of times- none of which resulted in any joy. I vaguely recall going through this once before- with a similar ending circumstance with the changed IP. At least if it happens again, I’ll have this post to fall back on.