Right after upgrading from RC1 to RC3 I can no longer access sites like:
http://dictionary.reference.com/
http://www.titanpoker.com - my online poker applications can also NO LONGER connect to their servers.
What could be the problem and how could I fix it?
Many thanks in advance.
DK
this can’t be related to routeros. how do you connect, are you using PPPoE? are you using firewall, proxy or some other specific setup?
I am using PPPoE on the ADSL modem (DHCP client on the router). No specific firewall or setups. All was working fine with RC1 before upgrading to RC3. Everything is normal if bypassing the hotspot/router (if plugged straigth into the ADSL modem). I got no additional scripts/firewall/mangle rules - just default hotspot setup using winbox.
Could someone with RC3 (preferably installed in a PC) check the above mentioned sites for me?
Thanks heaps!
I can, and of course they work. You probably have an MSS problem because you use PPPoE:
http://wiki.mikrotik.com/wiki/MikroTik_RouterOS_Frequently_Asked_Questions_-_FAQ#TCP.2FIP_Related_Questions
I tried the suggestion from Frequently_Asked_Questions without success. Please help!
[admin@MikroTik] /ip firewall mangle> print
Flags: X - disabled, I - invalid, D - dynamic
0 chain=forward action=change-mss new-mss=1448 tcp-flags=syn protocol=tcp
I cannot surf some sites when I use PPPoE.
Use /ip firewall mangle to change MSS (maximum segment size) to a value less 40 bytes your connection MTU. For example, if you have encrypted PPPoE link with MTU=1492, set the mangle rule as follows:/ ip firewall mangle
add chain=forward protocol=tcp tcp-flags=syn action=change-mss new-mss=1448
Also I was wondering why it was working with RC1 and now not with RC3???
Upgraded to RC4 no help.
Downgraded to RC2 no help.
Downgraded to RC1 everything works again - WOOHOO…
Definitely something not quite right about the later releases and it could be NOT just because we use PPPoE. I really hope that MT would take another look at this problem.
Did you solve this problem? I’m experiencing a similar problem with DNS..
Lollo,
Unfortunately, no! What I did was simply downgraded it to RC1 which was known to be working alright without DNS problem. All the later candidate releases appear troubled to me. If the problem is not solved, I am basically stuck with RC1 
I have tried changing MTU and MSS settings without success.
If the use of PPPoE maybe the cause of the DNS problem, I was wondering why it works with RC1 and also why MT would not help general users by integrating the fix/correct settings to allow for this in their software? It would make my day if RC5 changelog has something like this:
*) fixed DNS problem for PPPoE users 
Just to add that this problem persists for both PPPoE and DHCP-client for IP configurations and changing MTU settings does not help!