Draytek Vigor IPPBX 2820n, User Manual

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VigorIPPBX 2820 Series User’s Guide 256
once they re-construct the packets. The Vigor routers will
block any packets realizing this attacking activity.
Block ICMP Fragment Check the box to activate the Block ICMP fragment function.
Any ICMP packets with more fragment bit set are dropped.
Block Unknown
Protocol Check the box to activate the Block Unknown Protocol
function. Individual IP packet has a protocol field in the
datagram header to indicate the protocol type running over the
upper layer. However, the protocol types greater than 100 are
reserved and undefined at this time. Therefore, the router should
have ability to detect and reject this kind of packets.
Warning Messages We provide Syslog function for user to retrieve message from
Vigor router. The user, as a Syslog Server, shall receive the
report sending from Vigor router which is a Syslog Client.
All the warning messages related to DoS Defense will be sent to
user and user can review it through Syslog daemon. Look for the
keyword
DoS in the message, followed by a name to indicate
what kind of attacks is detected.