157
option. Only RawIP supports this flag.
• INP_PROTOCOL_PACKET—Identifies a protocol packet.
• INP_RCVVLANID—Receives the VLAN ID of the packet. Only UDP
and RawIP support this flag.
• INP_RCVMACADDR—Receives the MAC address of the frame.
• INP_SNDBYLSPV—Sends through MPLS.
• INP_RECVTOS—Receives TOS of the packet. Only UDP and
RawIP support this flag.
• INP_SYNCPCB—Waits until Internet PCB is synchronized.
• N/A—None of the above flags.
Inpcb vflag
IP version flags in the Internet PCB:
• INP_IPV4—IPv4 protocol.
• INP_TIMEWAIT—In TIMEWAIT state.
• INP_ONESBCAST—Sends broadcast packets.
• INP_DROPPED—Protocol dropped flag.
• INP_SOCKREF—Strong socket reference.
• INP_DONTBLOCK—Do not block synchronization of the Internet
PCB.
• N/A—None of the above flags.
TTL TTL value in the Internet PCB.
ip forward-broadcast
Use ip forward-broadcast to enable an interface to receive and forward directed broadcast packets
destined for the directly connected network.
Use undo ip forward-broadcast to disable an interface from receiving and forwarding directed
broadcast packets destined for the directly connected network.
Syntax
ip forward-broadcast
undo ip forward-broadcast
Default
An interface cannot receive or forward directed broadcasts destined for the directly connected
network.
Views
Interface view
Predefined user roles
network-admin
Usage guidelines
A directed broadcast packet is destined for all hosts on a specific network. In the destination IP
address of the directed broadcast, the network ID identifies the target network, and the host ID is
made up of all ones.
If an interface is allowed to forward directed broadcasts destined for the directly connected network,
hackers can exploit this vulnerability to attack the target network. In some scenarios, however, an
interface must receive and send such directed broadcast packets to support UDP helper.
To Next Page
Loading...
Need help?
General