KHNOG Micro-Event October 2015 Mr. Mike Geartner

1. a
little
something
about
BGP
Mike
Gaertner,
Sabay
Digital

2. ah?
Ê what
is
the
internet
Ê who
controls
it?
Ê what
problem
does
BGP
solve
Ê how
to
get
free
internet
(yes
that’s
a
lie,
but
stay
to
learn
the
truth)
Ê BGP
at
Sabay
practical
stuff

3. what
is
the
internet,
really?
Ê a
collection
of
52059
autonomous
systems
(AS)
on
Oct
15
2015
Ê each
network
has
a
number
of
IP
address,
group
into
prefix
Ê
575,609
prefix
are
visible
in
the
global
routing
table
Ê no
government
regulations

4. who
is
in
charge?

5. how?
Ê if
you
have
IP
address
space
from
APNIC
they
will
assign
you
a
AS
number
for
free
J
Ê AS
numbers
used
on
the
internet
to
identify
each
of
the
52000
participating
networks
Ê anyone
can
get
a
IP
address
range
from
APNIC
if
they
can
demonstrate
the
need
it
Ê the
need
arises
if
you
connect
to
more
then
1
ISP
and
you
have
infrastructure
that
will
use
50%
of
the
allocation
within
1
year

6. BGP
Ê DNS
is
the
address
book
of
the
internet
Ê BGP
is
the
mapping
software
of
the
internet
Ê it
glues
together
52,000
networks
and
remembers
at
its
core
where
to
find
over
570,000
prefixes
/
destination
networks
Ê BGP
in
it’s
most
simple
form
connects
2
network
Ê it
is
established
between
2
AS
numbers
and
it
exchanges
information
about
prefixes
own
by
each
AS
and
installs
a
route
for
each
prefix
(mostly)

7. what
is
a
prefix?
118.67.200.0/21
118.67.200.0/24
118.67.201.0/24
118.67.202.0/24
118.67.203.0/24
118.67.204.0/24
118.67.205.0/24
118.67.206.0/24
118.67.207.0/24
118.67.200.0/23
118.67.202.0/23
118.67.204.0/23
118.67.206.0/23
118.67.200.0/22
118.67.204.0/22
if
you
wonder
how
52,000
networks
can
have
570,000
prefixes,
that’s
how!
pollution
is
the
right
word

8. in
the
beginning
Ê BGP
was
designed
during
a
break
at
a
IETF
meeting
in
January
1989
in
Texas,
Austin
Ê 3
napkins
where
used
to
“invent”
the
core
concepts
Ê by
October
1989
at
the
IETF
meeting
in
Hawaii
version
BGP-­‐v2
was
introduced
Ê 1991
BGP-­‐v3
was
being
used
at
a
peer-­‐by-­‐peer
bases,
Cisco
adding
support
for
BGP
Ê 1993
most
networks
had
implemented
BGP-­‐3,
facing
out
EGP
Ê 1994
BGP-­‐v4
universal
adoption
at
tier
1
carriers

9. BGP
get
connected
Ê so
you
have
your
IP
space,
got
your
ASN
and
now?
Ê get
connected
Ê transit,
you
buy
access
to
the
internet
from
a
transit
provider
Ê peer
direct
with
friendly
networks
Ê or
peer
at
a
free
peering
exchange
like
CNX

10. Cambodia
-­‐
transit

11. Peers
at
CNX
you
can
reach
every
internet
user
in
Cambodia
via
CNX
peers
for
free

12. BGP
@
Sabay
–
our
peering
7712
CORE
TCT
CNX
SI
7712
DC
204/23
PPPoE
201/24
Backup
200/24
Content
202/24
Games
MKN

13. BGP
@
Sabay
-­‐
our
routing
policy
Ê we
want
to
deliver
content
as
cheap
as
possible
and
as
fast
as
possible
to
users
in
Cambodia
Ê we
want
to
give
out
customers
a
smooth
internet
access
experience
Ê remember:
Ê
routes
you
import
decided
your
outgoing
traffic
routes
Ê what
you
export
decides
how
traffic
gets
to
you

14. • TCT
• 0.0.0.0/0.0.0.0
• CNX
• everything
<
/24
• highest
local
preference
• MKN
• everything
<
/24
• second
highest
local
preference
• SI
• nothing
BGP
@
Sabay
-­‐
import
policy
7712
TCT
CNX
SI
MKN

15. default
only?
7712
TCT
SI
HK
SIN
EU
US
NY
DC
You
are
only
in
charge
of
selecting
the
first
hop
a
packet
may
travel
to
it
destination!

16. BGP
@
Sabay
–
export
policy
7712
TCT
CNX+
MKN
SI
118.67.200.0/21
118.67.200.0/24
(content)
118.67.202.0/24
(game)
remember
what
you
export
controls
how
traffic
comes
to
you!
the
net
+1

17. BGP
export
–
puts
you
in
control
7712
TCT
MKN
118.67.200.0/21
118.67.200.0/21
If
we
only
announce
118.67.200.0/21
then
ISP
X
can
choose
which
way
he
want
to
send
traffic
to
us.
ISP
X

18. BGP
export
–
puts
you
in
control
7712
TCT
MKN
ISP
X
118.67.200.0/21
118.67.200.0/21
118.67.200.0/24
118.67.200.0/24
but
if
announce
important
parts
of
our
network
only
via
the
free
peering,
then
we
can
ensure
traffic
for
our
content
will
be
delivered
via
our
free
link.

19. BGP
communities
7712
TCT
GGC
118.67.200.0/21
118.67.200.4/23
-­‐
7712:5555
very
simple,
community
means
a
extra
bit
of
information
per
prefix.
the
net
118.67.200.0/21