Problem accessing websites when I set up / 29 on the lan interface of my BGP box

RouterOS Forwarding Protocols
1

Hello everyone,

I’m turning to the forum, because I’m having a strange problem, which I’ve tried to solve alone and with friends and no idea what it can be or if it’s a device problem.

Come on, I have a box, CCR1009 and two BGP connected link, normal, I have clients that are connected via PPPoE / 32. and everything is working OK.

What’s the problem ?

If I set up a / 30, / 29 with PUBLIC IP or any other block, in an interface with computer directly connected in the box that makes BGP, WEB connection does not work,. NETFLIX the page does not open, in PING connection test for NETFLIX itself it works but WEB browsing does not, facebook and youtube working normal, however several other sites does not open, however if I get the same IP that is inside that / 30 and configure a PPPOE / 32 connection works normally.

I’ve tried several tests, when set up / 29, DNS OK test resolves, ping test for pages that does not open, I have answers, normal MTU, tested other notebook, tested others track of the public IP block, I have firewall rules, disabled all and I did test and it still persists, I disabled my balckhole for my entire block and split, however persisted, routing problem or IP blockage can not be because if it would not work when I set the same IP on a PPPOE connection.


Anyone have any suggestions on what the problem might be?

2

/ip firewall mangle add chain=forward action=change-mss new-mss=clamp-to-pmtu passthrough=yes tcp-flags=syn protocol=tcp in-interface=WAN tcp-mss=1361-65535 log=no log-prefix=“”
/ip firewall mangle add chain=forward action=change-mss new-mss=clamp-to-pmtu passthrough=yes tcp-flags=syn protocol=tcp out-interface=WAN tcp-mss=1361-65535 log=no log-prefix=“”

3

Hello boscolopez,

sorry for the delay to respond, so I checked, you suggested changing the MSS, right?

so I checked the default MSS would be 1460 being 1500 L3 MTU - 20 bytes Frame header, and - 20 Bytes IP header, so I checked how my connection is and are within that standard as you can see the image below the MSS.

I already checked everything that could be and I did not find anything and I still continue with this problem, is loading to open several sites, local, netflix, whatsapp among others.