What would cause one single ip address not to work? The mikrotik assigns the ip address to the modem but I am not able to surf the web. All other ip addresses in the block work except this one ip. We use PPPoE if that makes a difference. Thanks Kevin
Hello,
If the issue follows the IP, check for firewall rules or anything in the routing table that might be interfering.
I have seen this kind of issue also if two formerly separate IP ranges are joined into one, say two /25’s are merged into one /24, the PPPoE customer who lands on the .127 IP that used to be the broadcast for the /25 that no longer exists will not have service, due to a route caching bug in RouterOS. We needed to reboot the PPPoE concentrator to clear the cached route.
If I remember correctly we tried using that ip testing of dhcp, but removed the dhcp months ago. From what your wrote Im guessing you rebooted the router to clear everything, or do I need to upgrade to newest release?
No, we simply rebooted it to clear the cache. We didn’t want to because it takes down a large number of customers for a short time, but in our case it was a subnet that had been packed with /29’s and /30’s and those were moved to a different range months before and the old range they were in became a single simple /24 (but the router was never rebooted in between), and many customers who happened to be unlucky enough to land on the broadcast address for an old /29 or /30 that used to exist on the router had no connectivity. We couldn’t remember all of the /29’s and /30s that used to exist in that range to set up some kind of range exclusion for them, so the best solution was to reboot.
The reboot worked. Cleared everything out and the ip address works again. Thanks for your help