PPPOE users under MA5200 could access network, and they could run QQ, but they cannot open webpages although VLAN users are normal.
1. In checkup, the users have been online; the client can ping to both gateway and DNS, as well as the the website domain name, indicating both route and DNS are normal.
2. Ping big packet of 1500 does not communicate. Try smaller packets, and it is found that only the packets of less than 1000-byte could be pinged through; those more than 1000-byte cannot pinged through.
3. Check the online information of users; both downstream and upstream bandwidth for users are all 8Kbps; execute debug radius packet command, and it is found that the bandwidth allocated by radius is:
[Class(25)]   (Note: The value of CLASS is 32-bit in total, being divided into four octets from the left to right, which represet for upstream peak value, upstream average value, downstream peak value and downstream average value respectively).
The four parameters are less than 8K. The minimum bandwidth granularity of MA5200 is 8K, so the bandwidth for users to be online is 8K. Therefore, only the packets of less than 1000 octets could be pinged through, and those larger than 1000octets cannot be through, and users cannot open webpages. Modify the setting for bandwidth at radius, and users dial in again, so they can open the webpages now.
4. Why are VLAN users normal at the time? This is because VLAN users are using local authentication and the bandwidth of 10Mbps at the domain by default, so VLAN users can access network normally.
1. DNS in the address pool fro PPPOE users is configured falsely, and the DNS the users get cannot resolve the IP address of website.
2. MTU is problematic.
3. Bandwidth for users is too little.
The case is caused by third possibility.