Allied Telesis Routers and Switches manuale d’uso

C6 13- 1608 8-0 0 REV A www .alliedtelesis .com Ho w T o | Int r od ucti on In man y Server Hosting envir onme nt s, two requi rements are impor tant: maximising thr o ughput a vailability to each ser vice, a nd minimising ser vice downtime. This H ow T o Note co ntribu tes towards both these a ims. Th e Note is split into two par ts. The fir st pa[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 2 The Note’ s second example extends the f irst exa m p le by showi ng how to contr ol server sele ction for SFTP (Se cure File T rans fer Pr ot ocol) traff ic, while st ill providing ser ver r edu n dancy if the pr ef erred ser v er fails. For simplicity , th ese [...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 3 Exampl e of Basic Re dundan cy Confi gure Load Bal ancer 1 Name thi s r ou ter LB -1. set system name=LB-1 Crea te the thr ee VLANs t hat th is example use s: • VLAN 2 for the public Inter net side create vlan=vlan2 vid=2 • VLAN 3 for the priv ate LAN sid e cre[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 4 Enabl e the fi rewa ll. enable firewall Create a fire wa ll policy . create firewall policy=lb Set the f ire wal l session t imeouts f or TCP , UDP and other pack et types, in mi nutes. set firewall policy=lb tcptimeout=5 udptimeout=5 othertimeout=5 Add th e public[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 5 Configur e VRRP fo r the private side i nterface. This step cr eates a vir tual addr ess fo r the priva te interfac e of both loa d balancin g r out ers. Priv ate ser vers use th is addr es s as their gatewa y to the Int ernet, instead of usi ng the addr ess of the[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 6 If one of the load balan cers goes down, th e fir ewall con figuration nee ds to cha nge . This example uses t r ig gers t o m ak e this cha nge automatica lly , by running a script when the st ate changes. See "C r eate the Scripts " on pa ge 9 for instr[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 7 Confi gure Load Bal ancer 2 Load balancer 2 is id entical to lo ad balancer 1 , except for its: • name (which is jus t a con veni ence and d o es no t aff ect how it functio ns) • public interf ace’ s IP address • pr ivat e in te rf ac e’ s I P addr ess ?[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 8 Either: disable gui disable http server Or : set http server port=8080 enable vrrp create vrrp=2 over=vlan3 ipaddress=192.168.1.202 enable lb add lb respool=web selectmethod=roundrobin faillast=no add lb resource=web1 ip=192.168.1.1 port=80 respool=web add lb resou[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 9 Create the Scripts This s ection des cribes the s cripts that the trigger facility ru ns when the master or s la ve load balancer cha nges. Cr eate the same scri pts o n both load balancer 1 a nd load ba lancer 2. Crea te the scri pts in a te xt e ditor on yo ur PC[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 10 Ext en sion: Cont r oll ing S er v e r Sele ct ion Sometimes you ma y pr efer y our customers to access a cert ai n ser ver f o r certain traffi c types. H o wever , if that ser ver fails, they still require redundan cy to an altern ate ser ver . This sect ion sh [...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 11 Config ure the T rigg ers: E xtra C omma nds When the pr ef erred ser v er go es down or comes back up a ga in , the lo ad balancer ne eds to change to t he appr opriate res our ce . This exa mple uses t riggers t o mak e this change automatical ly , by runni ng a[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 12 Cr eat e N e w Scr i pts Th is section des cribes the s cripts t hat the trig ger facility runs wh en the prefe rred SFTP server g o e s down or comes b ack up again. The sc ripts enabl e and dis able the second r esour ce . L oad the sa me scripts onto both l oad[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 13 Confi gurat ion Summ ar y This sect ion sh ows the full extended confi gurations and scr i p ts, wit hout comments. Com mands: Lo ad Balance r 1 set sy s na me =LB-1 crea te v lan= vla n2 v id =2 crea te v lan= vla n3 v id =3 crea te v lan= vla n4 v id =4 add vl a[...]

Con figure Lo ad Balan cer Red un dancy on Allied T e lesis Route rs and Sw itches 14 Com mands: Lo ad Balance r 2 set sy s na me =LB-2 crea te v lan= vl an2 v id =2 crea te v lan= vl an3 v id =3 crea te v lan= vl an4 v id =4 add vl an =2 p ort=1 add vl an =3 p ort=2 -4 add vl an =4 p ort=5 enab le i p add ip int =v lan2 ip =1 72.2 14 .1 .4 mask =2[...]

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