The document provides an overview of a webinar hosted by GLC Networks on ISP load balancing, focusing on Equal Cost Multi-Path (ECMP) techniques. It includes information about the company, the webinar's agenda, prerequisites, trainer introduction, and various methods of load balancing. Additionally, it highlights potential issues, recommendations for best practices, and resources for further learning.

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ISP load balancing with
GLC webinar, 16 november 2017
Achmad Mardiansyah
achmad@glcnetworks.com
GLC Networks, Indonesia
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ECMP

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Agenda
● Introduction
● Prerequisite
● Load balancing
● ECMP method
● Demo
● Q & A
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What is GLC?
● Garda Lintas Cakrawala (www.glcnetworks.com)
● An Indonesian company
● Located in Bandung
● Areas: Training, IT Consulting
● Mikrotik Certified Training Partner/Consultant/Distributor
● Ubiquiti Certified Trainer/Consultant
● RedHat Certified Trainer
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About GLC webinar?
● First webinar: january 1, 2010 (title:
tahun baru bersama solaris - new
year with solaris OS)
● As a sharing event with various
topics: linux, networking, wireless,
database, programming, etc
● Regular schedule: every 2 weeks
● Irregular schedule: as needed
● Checking schedule:
http://www.glcnetworks.com/main/sc
hedule
● You are invited to be a presenter
○ No need to be an expert
○ This is a forum for sharing: knowledge,
experiences, information
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Trainer Introduction
● Name: Achmad Mardiansyah
● Base: bandung, Indonesia
● Linux user (since 1999), Mikrotik user (since 2007),
ubnt user (since 2011)
● Certified Trainer (Mikrotik, Ubiquiti, Redhat)
● Certified Consultant
● Work: Telco engineer, Sysadmin, PHP programmer,
and Lecturer
● Personal website: http://achmadjournal.com
● More info:
http://au.linkedin.com/in/achmadmardiansyah
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Please introduce yourself
● Your name
● Your company/university?
● Your networking experience?
● Your mikrotik experience?
● Your expectation from this course?
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Prerequisite
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wait, load balancing is easy...
● Lots of tutorials in internet!!!
● Tons of pages, tutorials, videos
Questions to reader:
● Do you really understand what its
written?
● Did the writer understand what
they wrote?
● Is it really works as expected in
your environment?
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Well if it's easy, why these do not work?
● Information overloaded… which
one suits you?
● Perhaps they have different
network environment compared
to you
● You need to understand how it
works...
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You should understand
● Firewall mangle. See GLC webinar: Mikrotik
firewall mangle
● The differences between:
○ Packet vs Connection
○ Mark: packet / connection / routing
● How routing works: see GLC webinar:
Routing with mikrotik
● How NAT works: see GLC webinar: Mikrotik
firewall NAT
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Load balancing
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What is (traffic) load balancing?
● Is a process to forward traffic on several
links
● Applied on router
● Load balancing != failover
● Can be done on per-packet or
per-connection basis
● This doesnt increase your data rate.
4mbps ISP1 + 4mbps ISP2 -> your
download rate = 8mbps (WRONG!)
Benefits:
● Increase utilisation of upstream links
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ISP1 ISP2
LAN
ether1 ether2
webserver
ISP3
ether4
R1

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Load balancing techniques
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Method Per-connection per-packet
Firewall marking YES YES
ECMP (our focus) YES NO
PCC YES NO
Nth YES YES
Bonding NO YES
OSPF YES NO
BGP YES NO

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Website contents: single connection
Website with single connection:
http://test.glcnetworks.com
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ISP1 ISP2
LAN
ether1 ether2
ISP3
ether4
R1

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Website contents: multi connection
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ISP1 ISP2
LAN
ether1 ether2
ISP3
● Client will open multiple connections to get
website components
Connect
ion 1
Connect
ion 2
Connect
ion 3
ether4
R1

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ECMP technique
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How ECMP works?
ECMP = Equal Cost Multi-Path ECMP. steps:
● ECMP will identify connections from clients
(per-src-dst-address combination)
● ECMP will forward the connection based on
weight/cost of the gateway
● ECMP does persistent per-connection load
balancing
● Its recommended to use “check-gateway” option
● As soon as one of the gateway is not responding,
check-gateway will remove it from gateway list,
and you will have a "failover" effect.
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ISP1
LAN
ether1
ISP3
conn 1
conn 2
conn 3
ISP2
ether2
ether4

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ECMP Example
● Using 2 gateways with same cost (e.g. both have same datarate)
/ip route add dst-address=0.0.0.0/0 gateway=10.10.11.1,10.10.12.1
check-gateway=ping
● Using 2 gateways with different cost (e.g. ISP2 is 2 times more than ISP2)
/ip route add dst-address=0.0.0.0/0
gateway=10.10.11.1,10.10.12.1,10.10.12.1 check-gateway=ping
● Using 3 gateways with different cost (e.g. ISP1=1mbps, ISP2=2mbps,
ISP3=3mbps)
/ip route add dst-address=0.0.0.0/0
gateway=10.10.11.1,10.10.12.1,10.10.12.1,10.10.13.1,10.10.13.1,10.10.13.1
check-gateway=ping
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ECMP via GUI
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Some issues
● Beware of NAT connection
○ webserver will see inbound connection from 2 ip public addresses
○ webpage will not displayed correctly (as it is considered illegal session)
○ banking / https / game websites will not allow you to access their website, because they will
see you are coming from 2 more IP addresses. often you need to do authentication again
● Beware of DNS rules
○ Some DNS server will give different result based on source IP address -> could make website
inaccessible
● Routing table flushing
○ Routing table is flushed every 10 minutes, to avoid possible DOS attack
○ Your persistent route will be created again -> this could lead to a new IP address (if you use
NAT)
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Recommendations
● Avoid NAT if possible -> dont use private address -> use public IP address
end-to-end -> use BGP -> better performance
● Use IPv6 -> IPv6 is designed to have a large address space
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Interested? Just come to our training...
Just go to http://www.glcnetworks.com/schedule
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End of slides
● Thank you for your attention
● Please submit your feedback: http://bit.ly/glcfeedback
● Like our facebook page: “GLC networks”
● Slide: http://www.slideshare.net/r41nbuw
● Recording: https://www.youtube.com/channel/UCI611_IIkQC0rsLWIFIx_yg
● Stay tune with our schedule
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