Hai!
It has been four months i’ve been using mikrotik..i have gain a lot of knowledge and experience along the way..now i have 4 mikrotik routeros running for my clients! 
thank you to mikrotik forum and mikrotik support for assisting me and sharing the knowledge.
I would like to post this question to all..
One of my mikrotik routeros is running on two LANs and one WAN. The two LANs reside on different interface. LAN A is assigned to IP address 192.yyy.yyy.1/24; and LAN B is assigned to IP address 10.zzz.zz.1/24 with DHCP enabled.
These are the IP address of the interfaces:
# ADDRESS NETWORK BROADCAST INTERFACE
0 192.yyy.yyy.1/24 192.yyy.yyy.0 192.yyy.yyy.255 LAN A
1 10.xxx.x.xxx/24 10.xxx.x.0 10.xxx.x.255 WAN
2 10.zzz.zz.1/24 10.zzz.zz.0 10.zzz.zz.255 LAN B
The ip route is:
# DST-ADDRESS PREFSRC G GATEWAY DISTANCE INTERFACE
0 ADC 10.xxx.x.0/24 10.xxx.x.xxx WAN
1 ADC 10.zzz.zz.0/24 10.zzz.zz.1 LAN B
2 ADC 192.yyy.yyy.0/24 192.yyy.yyy.1 LAN A
3 A S 0.0.0.0/0 r 10.aaa.a.aaa WAN
I received lots of complains from my clients which use LAN B saying that the internet is slow. When i winbox into the mikrotik, i could see that LAN A is transmitting and receiving in high rate but LAN B is transmitting and receiving very low. I didn’t receive any complaints from clients on LAN A. I use torch to see the realtime traffic flow. This is what i get:
LAN A:
PRO.. TX RX TX-PACKETS RX-PACKETS
tcp 947.4kbps 901.9kbps 178 249
LAN B:
PRO.. TX RX TX-PACKETS RX-PACKETS
tcp 120kbps 3kbps 10 8
I don’t understand why is this happening..i assumed that could be because these two LANs share the same gateway. So i did a routing rule to force LAN A to use gateway 1 while LAN B use gateway 2. I add this ip firewall mangle:
0 chain=prerouting src-address=10.zzz.zz.0/24 action=mark-routing
new-routing-mark=net1 passthrough=yes
1 chain=prerouting src-address=192.yyy.yyy.0/24 action=mark-routing
new-routing-mark=net2 passthrough=yes
Then the ip route is:
# DST-ADDRESS PREFSRC G GATEWAY DISTANCE INTERFACE
0 ADC 10.xxx.x.0/24 10.xxx.x.xxx WAN
1 ADC 10.zzz.zz.0/24 10.zzz.zz.z LAN B
2 ADC 192.yyy.yyy.0/24 192.yyy.yyy.y LAN A
3 A S 0.0.0.0/0 r 10.aaa.a.aaa WAN
4 A S 0.0.0.0/0 r 10.bbb.b.bbb WAN
After i did that, LAN B shows trasmitting and receiving much better. And the internet surfing is much faster. However, it didn’t last. After a few minutes..the problem occurs again. I am so confused why is this happening? Could anyone help me please…is there a better solution to this? thank you.