User manual TP-LINK TL-SG5426 INSTALLATION GUIDE

[. . . ] TL-SG5426 26-Port Gigabit Managed Switch Rev: 1. 0. 0 1910010105 COPYRIGHT & TRADEMARKS ® is a registered Specifications are subject to change without notice. Other brands and product names are trademarks or registered trademarks of their respective holders. No part of the specifications may be reproduced in any form or by any means or used to make any derivative such as translation, transformation, or adaptation without permission from TP-LINK TECHNOLOGIES CO. , LTD. http://www. tp-link. com FCC STATEMENT This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. [. . . ] · If a DHCP packet from a client passes the filtering criteria above, it will only be forwarded to trusted ports in the same VLAN. · If a DHCP packet is from server is received on a trusted port, it will be forwarded to both trusted and untrusted ports in the same VLAN. If the DHCP snooping is globally disabled, all dynamic bindings are removed from the binding table. Additional considerations when the switch itself is a DHCP client ­ The port(s) through which the switch submits a client request to the DHCP server must be configured as trusted. Note that the switch will not add a dynamic entry for itself to the binding table when it receives an ACK message from a DHCP server. Also, when the switch sends out DHCP client packets for itself, no filtering takes place. However, when the switch receives any messages from a DHCP server, any packets received from untrusted ports are dropped. DHCP Snooping Configuration Command Attributes · DHCP Snooping Status ­ Enables or disables DHCP snooping globally. · DHCP Snooping MAC-Address Verification ­ Enables or disables MAC address verification. DHCP packets will be dropped if the source MAC address in the Ethernet header of the packet is not same as the client's hardware address in the DHCP packet. Web ­ Click DHCP Snooping, Configuration. Figure 3-114 DHCP Snooping Configuration CLI ­ This example first enables DHCP Snooping, and then enables DHCP Snooping MAC-Address Verification. Console(config)#ip dhcp snooping Console(config)#ip dhcp snooping verify mac-address Console(config)# 4-231 4-235 3-187 3 Configuring the Switch DHCP Snooping VLAN Configuration Enables DHCP snooping on the specified VLAN. (Range: 1-4094) · DHCP Snooping Status ­ Enables or disables DHCP snooping for the selected VLAN. When DHCP snooping is enabled globally on the switch, and enabled on the specified VLAN, DHCP packet filtering will be performed on any untrusted ports within the VLAN. Web ­ Click DHCP Snooping, VLAN Configuration. Figure 3-115 DHCP Snooping VLAN Configuration CLI ­ This example first enables DHCP Snooping for VLAN 1. Console(config)#ip dhcp snooping vlan 1 Console(config)# 4-233 DHCP Snooping Information Option Configuration DHCP provides a relay mechanism for sending information about the switch and its DHCP clients to the DHCP server. Known as DHCP Option 82, it allows compatible DHCP servers to use the information when assigning IP addresses, or to set other services or policies for clients. When the DHCP Snooping Information Option is enabled, clients can be identified by the switch port to which they are connected rather than just their MAC address. DHCP client-server exchange messages are then forwarded directly between the server and client without having to flood them to the entire VLAN. In some cases, the switch may receive DHCP packets from a client that already includes DHCP Option 82 information. The switch can be configured to set the action policy for these packets. Either the switch can discard the DHCP information, keep the existing information, or replace it with the switch's relay information. Note: DHCP snooping must be enabled on the switch for the DHCP Option 82 information to be inserted into packets. 3-188 DHCP Snooping Command Attributes 3 · DHCP Snooping Information Option Status ­ Enables or disables DHCP Option 82 information relay. · DHCP Snooping Information Option Policy ­ Sets the DHCP snooping information option policy for DHCP client packets that include Option 82 information. · Replace ­ Overwrites the DHCP client packet information with the switch's relay information. [. . . ] This is related directly to the hardware interface for network devices and passes on traffic based on MAC addresses. Link Aggregation See Port Trunk. Link Aggregation Control Protocol (LACP) Allows ports to automatically negotiate a trunked link with LACP-configured ports on another device. Management Information Base (MIB) An acronym for Management Information Base. It is a set of database objects that contains information about a specific device. MD5 Message-Digest Algorithm An algorithm that is used to create digital signatures. It is intended for use with 32 bit machines and is safer than the MD4 algorithm, which has been broken. MD5 is a one-way hash function, meaning that it takes a message and converts it into a fixed string of digits, also called a message digest. Glossary-3 Glossary Multicast Switching A process whereby the switch filters incoming multicast frames for services for which no attached host has registered, or forwards them to all ports contained within the designated multicast VLAN group. Network Time Protocol (NTP) NTP provides the mechanisms to synchronize time across the network. [. . . ]