Enabling/Disabling Directed Broadcasts
Page 25-41
Enabling/Disabling Directed Broadcasts
An IP directed broadcast is an IP datagram that has all zeroes or all 1’s in the host portion of
the destination IP address. The packet is sent to the broadcast address of a subnet to which
the sender is not directly attached. The datagram is routed through the network as a unicast
packet. When it arrives at the subnet, it is converted into a broadcast packet.
Directed broadcasts are used in denial-of-service
smurf
attacks. In a smurf attack, a continu-
ous stream of ping requests are sent from a falsified source address to a directed broadcast
address, resulting in a large stream of replies, which can overload the host of the source
address.
By default, the switch drops directed broadcasts. Typically, directed broadcasts should not be
enabled.
To enable directed broadcasts to be routed through the switch:
1.
At the system prompt, enter the
ipdirbcast
command.
2.
Enter
y
to enable direct broadcasts.
Содержание Omni Switch/Router
Страница 1: ...Part No 060166 10 Rev C March 2005 Omni Switch Router User Manual Release 4 5 www alcatel com ...
Страница 4: ...page iv ...
Страница 110: ...WAN Modules Page 3 40 ...
Страница 156: ...UI Table Filtering Using Search and Filter Commands Page 4 46 ...
Страница 164: ...Using ZMODEM Page 5 8 ...
Страница 186: ...Displaying and Setting the Swap State Page 6 22 ...
Страница 202: ...Creating a New File System Page 7 16 ...
Страница 270: ...Displaying Secure Access Entries in the MPM Log Page 10 14 ...
Страница 430: ...OmniChannel Page 15 16 ...
Страница 496: ...Configuring Source Route to Transparent Bridging Page 17 48 ...
Страница 542: ...Dissimilar LAN Switching Capabilities Page 18 46 ...
Страница 646: ...Application Example DHCP Policies Page 20 30 ...
Страница 660: ...GMAP Page 21 14 ...
Страница 710: ...Viewing the Virtual Interface of Multicast VLANs Page 23 16 ...
Страница 722: ...Application Example 5 Page 24 12 ...
Страница 788: ...Viewing UDP Relay Statistics Page 26 24 ...
Страница 872: ...The WAN Port Software Menu Page 28 46 ...
Страница 960: ...Deleting a PPP Entity Page 30 22 ...
Страница 978: ...Displaying Link Status Page 31 18 ...
Страница 988: ...Displaying ISDN Configuration Entry Status Page 32 10 ...
Страница 1024: ...Backup Services Commands Page 34 14 ...
Страница 1062: ...Diagnostic Test Cable Schematics Page 36 24 ...
Страница 1072: ...Configuring a Switch with an MPX Page A 10 ...
Страница 1086: ...Page B 14 ...
Страница 1100: ...Page I 14 Index ...