Zyxel XGS-4728F [260/491] Dhcp snooping overview

Zyxel XGS-4728F [260/491] Dhcp snooping overview
Chapter 26 IP Source Guard
XGS-4526/4528F/4728F User’s Guide
260
26.1.1 DHCP Snooping Overview
Use DHCP snooping to filter unauthorized DHCP packets on the network and to
build the binding table dynamically. This can prevent clients from getting IP
addresses from unauthorized DHCP servers.
26.1.1.1 Trusted vs. Untrusted Ports
Every port is either a trusted port or an untrusted port for DHCP snooping. This
setting is independent of the trusted/untrusted setting for ARP inspection. You can
also specify the maximum number for DHCP packets that each port (trusted or
untrusted) can receive each second.
Trusted ports are connected to DHCP servers or other switches. The Switch
discards DHCP packets from trusted ports only if the rate at which DHCP packets
arrive is too high. The Switch learns dynamic bindings from trusted ports.
Note: The Switch will drop all DHCP requests if you enable DHCP snooping and there
are no trusted ports.
Untrusted ports are connected to subscribers. The Switch discards DHCP packets
from untrusted ports in the following situations:
The packet is a DHCP server packet (for example, OFFER, ACK, or NACK).
The source MAC address and source IP address in the packet do not match any
of the current bindings.
The packet is a RELEASE or DECLINE packet, and the source MAC address and
source port do not match any of the current bindings.
The rate at which DHCP packets arrive is too high.
26.1.1.2 DHCP Snooping Database
The Switch stores the binding table in volatile memory. If the Switch restarts, it
loads static bindings from permanent memory but loses the dynamic bindings, in
which case the devices in the network have to send DHCP requests again. As a
result, it is recommended you configure the DHCP snooping database.
The DHCP snooping database maintains the dynamic bindings for DHCP snooping
and ARP inspection in a file on an external TFTP server. If you set up the DHCP
snooping database, the Switch can reload the dynamic bindings from the DHCP
snooping database after the Switch restarts.

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Здравствуйте! Свич Zyxel XGS-4728F в консоле видает : Bootbase Version: V1.00 | 10/22/2007 12:48:50RAM:Size = 128 MbytesDRAM POST: Testing:131072K OKDRAM Test SUCCESS !FLASH: Intel 64MCopyright (c) 1994 - 2011 ZyXEL Communications Corp.Data abort occuredFault Status = 0x000000F5Fault Addr = 0xE59FF570Current Task TCB = 0x0129ED10Current Task Name = PINICurrent Task Stack Start = 0x0129EDACCurrent Task Stack End = 0x012A5E2BAbnormal Stack Task List : NONE r0= 0x000000F5 r1= 0xE59FF570 r2= 0xE59FF018 r3= 0xE59FF000 r4= 0x00D135FC r5= 0xE59FF018 r6= 0x00D135FC r7= 0x00067FC0 r8= 0x00D135FC r9= 0x00000000 r10=0x00000004 fp= 0x012A5CD4 r12=0x00000000 sp= 0x012A5C14 lr= 0x00000564 pc= 0x0011DC40 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 12a5cc8: 01 2a 5d 08 01 2a 5c d8 00 11 e8 6c 00 11 d9 d8 .*]..*\.l. 12a5cd8: 00 00 00 00 00 00 00 00 01 1b 13 74 01 2a 5d 08 .t.*]. 12a5ce8: 00 d1 44 f8 00 cf a2 10 00 cf a3 38 00 00 00 00 ..D.8. 12a5cf8: 00 00 00 00 01 2a 5d 7c 01 2a 5d 0c 00 12 06 80 .*]|.*]. 12a5d08: 00 11 e7 90 00 08 c6 d4 00 65 7d 34 00 fe 12 b0 .e}4. 12a5d18: 01 2a 5d 34 01 2a 5d 28 00 09 b8 c4 00 08 c6 c8 .*]4.*]. 12a5d28: 01 2a 5d 4c 01 2a 5d 38 00 17 c9 3c 00 09 b8 c0 .*]L.*]8.<. 12a5d38: 00 fe 12 b0 00 00 00 00 01 2a 5d 64 01 2a 5d 50 .*]d.*]P 12a5d48: 00 17 c9 b8 00 09 bb e8 00 ae c1 58 00 ae c2 28 .X( 12a5d58: 01 2a 5d 7c 01 2a 5d 68 01 2a 5d 7c 00 d0 7b 44 .*]|.*]h.*]|..{D 12a5d68: 00 d0 7b 44 00 cf a2 10 01 2a 5e 10 01 2a 5d 80 ..{D.*^..*]. 12a5d78: 00 06 ff b8 00 12 06 5c 00 00 01 2c 23 f1 97 40 .\.,#..@ 12a5d88: 00 0e 68 c0 00 00 00 00 ef ef ef ef ef ef ef ef ..h. 12a5d98: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5da8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5db8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5dc8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5dd8: ef ef ef ef ef ef ef ef 00 00 00 01 00 00 00 53 .S 12a5de8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5df8: 00 00 00 00 00 00 00 00 00 00 00 00 01 2a 5e 20 .*^ 12a5e08: 01 2a 5e 14 00 65 80 4c 00 06 fd d4 00 00 00 00 .*^..e.L. 12a5e18: 01 2a 5e 24 00 00 00 00 00 65 80 2c 00 00 00 00 .*^$.e.,. 12a5e28: ef ef ef ef 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e38: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e48: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e58: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e68: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e78: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e88: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5e98: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5ea8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5eb8: 00 00 00 00 00 00 00 00 00 00 00 00 54 48 52 44 .THRD 12a5ec8: 00 00 00 01 01 2a 7e a0 01 2a 5f 60 01 2a 7f 5f .*~..*_`.*._ 12a5ed8: 00 00 20 00 00 00 00 00 00 00 00 00 01 2a 5e c4 .. .*^. 12a5ee8: 01 2a 5e c4 00 93 0c 50 00 00 00 04 00 00 00 03 .*^.P. 12a5ef8: 00 00 00 00 00 00 00 00 00 00 00 04 00 00 00 10 . 12a5f08: 00 00 00 00 00 08 d4 4c 01 2a 5e c4 00 00 00 00 .L.*^. 12a5f18: 00 00 00 00 00 65 89 30 01 2a 5e c4 00 00 00 00 .e.0.*^. 12a5f28: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5f38: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 . 12a5f48: 00 00 00 00 00 00 00 00 00 00 00 00 01 2a 7f f8 .*.. 12a5f58: 01 29 ed 10 00 00 00 00 ef ef ef ef ef ef ef ef . 12a5f68: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5f78: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5f88: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5f98: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5fa8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5fb8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5fc8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5fd8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5fe8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a5ff8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6008: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6018: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6028: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6038: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6048: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6058: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6068: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6078: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6088: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a6098: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a60a8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a60b8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef . 12a60c8: ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef ef .Bootbase Version: V1.00 | 10/22/2007 12:48:50RAM:Size = 128 MbytesFLASH: Intel 64M Как устранить проблему? Спасибо.
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