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Catalyst 2950 Desktop Switch Software Configuration Guide
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Ch apter 1 Overview
Features
•Address Resolution Protocol (ARP) for identifying a switch through its IP address and its
corresp ond in g MAC address
•Cisco Disc overy Protocol (CDP) version s 1 and 2 for networ k to pology disc overy and ma pping
betwee n th e switc h an d o the r C isco devices on t he n etwor k
•Network Time Protocol (NTP) for providing a consistent timestamp to all switches from an external
source
•Directed unicast requests to a Trivial File Transfer Protocol (TFTP) server for obtaining software
upgrade s from a TFT P se rver
•Default c onfiguration storage i n Flash memo ry to ens ure that th e switch ca n be connec ted to a
network and ca n forward t raffic with mi nima l user inter vention
•In-band ma nagement access thro ugh a CMS web-base d session
•In-band ma nageme nt acc ess through up to 16 simulta neous Telnet co nnecti ons for mu ltiple
comman d-l ine in terfa ce ( CL I)-ba sed se ssion s over the ne twork
•In-band management access through Simple Network Management Protocol (SNMP) versions 1, 2c,
and 3 get an d set reque sts
•Out-of-band management access through the switch console port to a directly-attached terminal or
to a remot e t erm in al th rough a se ria l c onn ect ion an d a mod em
Note For additional descriptions of the management interfaces, see the “Manageme nt Optio ns”
section on page 1-7.
Redundancy
•HSRP for c omm an d-swit ch r ed und ancy
•UniDir ect iona l li nk det ecti on (U D LD) on a ll E thern et po rt s fo r de tec ting an d disab lin g
unidirec tiona l l ink s on fiber-optic inte rfac es c a used by i ncor rec t fiber-optic wir ing or po rt fa ults
•IEEE 802. 1D Span ning Tree Protocol (STP) for redundant backbon e conne ctions and loop-f ree
networks. STP ha s these features:
–
Per-VLAN Spanning Tr ee (PVST) for balancing load across VLANs
–
UplinkFast, cross-stack UplinkFast, and BackboneFast for fast convergence after a
spannin g-tr ee t op ology ch ange a nd fo r ac hieving l oad b al anc ing bet wee n r edund an t up lin ks,
including G igabit upli nks and cross- stack Giga bit uplinks
•IEEE 8 02.1S Mu ltipl e ST P (MST P) for g rou ping V LANs in to a sp an ning- tre e i nstanc e, a nd
providing for multiple forwarding paths for data traffic and load balancing (available only with
the EI)
•IEEE 802. 1W Rapid STP (RSTP) for rapid convergence of the span ning tre e by immediately
transit ioning root and design ated por ts to the forwa rding state (available only with the EI)
•Optiona l sp ann ing- tr ee fe atur es avail able :
–
Port F ast for eliminating the forw arding delay by enablin g a port to immedia tely transition from
the blockin g state to th e forwarding state
–
BPDU guard for shutting down Port Fast-enable d ports that rec eive BPDUs
–
BPDU filtering for pr eventing a Port Fast-en abled po rt f rom se nd ing or rece iving BPDU s
–
Root gua rd for p reventing sw itches outsi de the network core from becoming the spanning-t ree
root