What is the reply code


Anti-spam performs legitimacy checks on the sender's IP address. If the IP address is blacklisted, the FW considers it junk email. To check the legitimacy of the source IP address using the RBL blacklist, the FW sends a query request to the RBL server and determines the legitimacy of the IP address based on the reply code returned from the RBL server.

A reply code is generally an IP address for identification only. It can be a reserved IP address, such as and

To use the RBL blacklist, obtain the reply code from the RBL service provider and set the reply code on the FW. After receiving the query result, the FW compares the returned reply code with the one specified on the device. If the codes match, the queried IP address is blacklisted and email from this IP address is junk email.

Other related questions:
Fast ICMP reply function on S series switches
After receiving an ICMP Request packet, an S series switch (a non-S1700 switch) does not send it to the ICMP protocol stack but directly exchanges the source and destination MAC addresses of the packet and responds with an ICMP Relay message. This process is called fast ICMP reply. (The switch can successfully ping another device even if it does not have a return route or an ARP entry.) A switch cannot accurately calculate the delay or jitter of ping packets that require high real-time performance. The reason is that the protocol stack adds the sending and receiving timestamps to ping packets. The packets need to enter queues frequently between the protocol stack and the hardware. Therefore, the real-time performance of timestamps cannot be ensured. In versions earlier than V100R006, fast ICMP reply is a common task. When a switch processes a large number of services, the reply delay is long due to service switching. In V100R006 and later versions, fast ICMP reply is a super task with a high priority. In most cases, the relay delay is about 1 ms. The actual delay depends on the CPU usage and is shorter than 100 ms. The icmp-reply fast command enables the fast ICMP reply function. Note: The fast ICMP reply function is disabled on modular switches running all versions by default.

What is the effect of excess ARP reply packets on the CPU
If excess ARP Reply packets are sent to the CPU, the CPU may be overloaded. Run the display cpu-defend configuration packet-type arp-reply all and display cpu-defend statistics packet-type arp-reply all commands to whether excess ARP Reply packets are sent to the CPU. In the display cpu-defend statistics packet-type arp-reply all command output. if the value of the Drop (Bytes) field is large, excess ARP Reply packets are sent to the CPU. In this case, adjust the CIR value for the ARP Reply packet. If the CPU is attacked, obtain the packet header or enable the debugging to trace the attack source and add the attack source to the blacklist.

What is the unified SMC2.0 access code?
If a user does not specify a conference access code, the Lync Client, ViewPoint 9000-series endpoint, TE series endpoint, and TP can call the unified access code and join a multi-point conference as promoted by the IVR. The unified access code is a string consisting of less than 13 digits. The default access code is 9000. The access code cannot be the first N characters of the conference access code. On the SMC2.0 page, the SMC2.0 administrator chooses System > Settings > Conference > Conference ID > Unified access number.

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