What can I do when ‘ethernet to modem PC works but router to PC doesn’t’?

Alright, so you\’re having no trouble connecting your PC directly to the modem with an Ethernet cable. But throw a router in the mix, and it all goes south? Let\’s dig into what might be happening and how you can sort it out.

Understanding What’s Happening:

When you wire your PC straight into the modem, it\’s like having a direct line to the internet. But the router’s job is to share that connection across different devices. If the router\’s flubbing its part, that\’s likely where your issue lies.

What Could Be Wrong and How to Fix It:

1. DHCP Server Hiccups:
   • If your PC is spitting out a weird \”No Internet\” message or giving you an IP starting with 169.254, your router\’s DHCP might be on the fritz.
   • Dive into your router’s settings (you can usually find it at 192.168.1.1), and see if the DHCP is up and running in the LAN settings. Ensure there’s room in the IP pool, and restart the DHCP service if it lets you.
2. Firewall Playing Hard to Get:
   • A firewall might be blocking the show, showing you limited or zilch connectivity.
   • Check the firewall rules on your router. For Linux-based routers, you’d use \”iptables -S\” to get a peek. Make sure it’s letting DHCP traffic through via ports 67 and 68. Temporarily drop the firewall for a bit just to see if that fixes things.
3. The Basics – Physical Connections:
   • No link light on your router or PC port? That’s a dead giveaway.
   • Swap out the Ethernet cables for something like Cat5e or newer. Test different LAN ports on the router. And hey, check if your network drivers are up-to-date while you’re at it.
4. MAC Address Blocking the Way:
   • Works on some gadgets but not your PC? Could be MAC address filtering.
   • Sneak a look at the MAC filtering settings in your router. Add your PC to the nice list, or just turn off the filtering for now to test.
5. IP Address Clash:
   • Getting iffy or spotty connections? Maybe there\’s an IP conflict.
   • Hop into the Command Prompt and try \”ipconfig /release\” and then \”ipconfig /renew\”. Or set a static IP outside the DHCP range as a temporary patch.

A Bit More In-Depth:

• Break out Wireshark if you want to see what the DHCP packets are up to between your PC and router.
• Peek at the router logs for any DHCP-related grumbles.
• See if the router’s bridge interface (br0) is doing what it should.
• Maybe borrow a buddy’s PC to see if it’s your network card being fussy.

Remember to give both the router and PC a nice, fresh restart after you make any of these tweaks. If nothing’s budging, a firmware update for the router or a good old factory reset might be your Hail Mary. Since the wired connection straight to the modem is working, you can relax knowing it\’s not your ISP. The router\’s probably the culprit here.

Hope this helps, and good luck getting everything back up and running!

Here’s a puzzle we all dread: Your PC works perfectly when connected directly to the modem, but all bets are off when you try using the router. Let’s break down some potential fixes to get everything running smoothly.

1. Start with the Basics:
   • Pop into your router’s settings via a web browser. Make sure DHCP is turned on so it can hand out IP addresses like candy.
2. Give Those Cables a Look:
   • Double-check for any sneaky damage on the cables. And don’t be shy—trying another cable never hurts.
   • If one router port’s being a diva, try another.
3. Poke Around in Network Settings:
   • Head into your PC’s control panel and dive into the Network and Sharing Center. Make sure you’re set to get an IP address automatically.
4. Is Your Router Outdated?
   • If your router’s playing a dated tune, it might need a firmware update from the manufacturer’s site.
5. When in Doubt, Reset:
   • I know, I know—losing settings is annoying. But sometimes giving your router a hard reset does wonders.
6. Your PC’s Drivers Need Some Love:
   • Make sure those network adapter drivers are fresh. Check the manufacturer’s site or poke around in Windows Device Manager.
7. Still Stuck?
   • If nothing’s working and smoke starts coming out of your ears, reach out to the router’s support team. They might have a trick or two up their sleeves.

Hopefully, after checking these tips, your router-to-PC problem will be a distant memory. It might take a bit of fiddling, but you’ll have your setup purring like a kitten in no time.

Dealing with a setup where your PC links up perfectly with the modem, but toss a router in the mix and suddenly everything goes haywire? Yeah, that can be a major buzzkill. Luckily, there are a few tweaks and checks you can do to get things back on track.

1. Physical connections and cables: Start with the obvious. Make sure those Ethernet cables aren\’t just loosely hanging in there. A wobbly cable could end up messing with your connection or give you snail-paced speeds. Swap ‘em out if they look beat-up.

2. Router settings and connections: Check where you’re plugging that router in. Mixing up the WAN and LAN ports is like trying to put a square peg in a round hole. It just doesn\’t work. Make sure DHCP is doing its thing, so your PC isn\’t left feeling lost without an IP address. If things are still funky, maybe try hitting “network reset” on the router to clear out any gremlins in the settings.

3. Modem constraints and MAC addresses: Sometimes, your ISP might have a little love affair going on with your PC’s MAC address, and ain\’t willing to share. Restarting the modem with the router connected can sometimes do the trick. If not, maybe clone your PC\’s MAC address onto the router and see if that smooths things out.

4. Power-cycling gear: Sounds simple, but turning things off and back on again is like a magic spell for tech troubles. Shut down both the modem and router, pull the plug, give it 30 seconds, and then fire them back up—modem first, then the router.

5. Updates on drivers and firmware: If your PC feels out-of-the-loop on the latest network adapter drivers, update them pronto. The router might be pleading for a firmware update as well. Outdated software can be like trying to read a text in a language you don’t speak—things get lost.

6. Network speeds and port checks: If your PC\’s connection speed reads like a sad story (let’s say 10 Mbps instead of something reasonable), it might be a port issue. Run some network diagnostic commands like “ipconfig /release” followed by “ipconfig /renew” to make sure your PC’s grabbing a proper IP. Also, if you’ve hooked up via a switch, make sure its settings aren’t off in la-la land.

By tackling these steps, you\’ll hopefully unearth what\’s gumming up the works. Whether it’s the cables, router jazz, hardware quirks, or driver shenanigans, each angle brings you a step closer to solving your issue. Good luck!