SOLARIS
NETWORKING-1
What we are going to Learn,
·
TCP/IP Layers basic
·
ARP
·
RARP
Great,
We almost touched Major topics From SA-1 / SA-2, but we did not get
in hand to hand with Networking Part of Solaris which is SA-3,
So, let’s dedicate few posts for Solaris Networking,
Well… Systems can talk with each other! Right??? Yes… ok then,
Agreed that Systems can talk, But How?
With the help of Network they are bound with… Means Servers / Routers
/ Switches / Hubs / Cables / Repeaters …. Whatever
Let’s imagine a scenario where 5 systems are connected within a
Network, Does they start talking like “Ooo hello… what are u doing… yes u man”
Can they talk in this manner? Even we does not communicate in such
way, we follow some manner & etiquettes while communicating. So does the
same thing applied on Systems? Yes!!!
They also follow some set of rules to communicate, and these rules
are called “PROTOCALS”……… And one thing here to consider is the communication
is based on data. So we are about to deal with “Data Communication Protocol”
“A data
communication protocol is a set of rules that must be followed for two
electronic devices to communicate with each other”
OK… Suppose we have
to send a 1000kg bag of rice to some place, there might be several media
through which we can send that like Train, Truck, Flight, etc…
Packet is ready,
media is decided, Now one last question.
Does it convenient
to send whole 1000kg bag or it will be better if we make 10, 100kb bags of
that?
Obviously 10… 100kb
bags are preferred over 1… 1000kg bag.
Let’s assume the
same scenario for our case,
1000kb bag is data we
want to send
Trains, Truck,
Airplane are Protocols
10…100kg bags Communication is broken into smaller
processes
There are many
Protocols that support data com, A communication architecture is formed by them
which is also known as Protocol Stack,
Solaris uses TCP/IP
model for its data communication, and obviously it’s a Protocol Stack.
TCP/IP model is a
layered architecture, and each layer has specific function which is needed to
be performed sequentially for successful data communication.
TCP/IP NETWORK MODEL
|
Layer
|
Description
|
|
APPLICATION
|
=It defines that
how the data will be represented
in network
=Manages user
applications program & network services
Examples-DNS,
FTP, HTTP, TELNET, NIS, NFS……
|
|
TRANSPORT
|
=Manages the
connection between applications
=Ensures that
message reach the correct application by using TCP (connection oriented) /
UDP (Connectionless) Protocols.
|
|
INTERNET
|
=Manages data
addressing and delivery between networks
=Fragments data
for the Network Interface layer
Examples- IP,
ARP, RARP, ICMP
|
|
NETWORK INTERFACE
|
= Manages the
delivery of data across the physical network
= Provides error
detection and packet framing
Examples-
ETHERNET, PPP, Token-Ring, FDDI
|
|
HARDWARE
|
=Describes the
Physical connectivity of Network
|
Hey NITA…. Just to
remember the Layers Name, from bottom to up.
I really apologize
that I am unable to write such long explanations about working of each layer,
RESOLUTION
PROTOCOLS
ARP ADDRESS
RESOLUTION PROTOCOL
RARP REVERSE
ADDRESS RESOLUTION PROTOCOL
Before explaining
both I just need to say one line,
“Hey… I have
something and I want something in return of that”
That line will explain both,
ARP = IP to MAC resolution
RARP = MAC to IP resolution
Suppose there are 50 Systems on the network, and the packet is
intended for 192.168.234.200 so it will be broadcasted over the network that
this packet is for said Ip, everybody will receive and process that packet, but
only the correct recipient will revert with its MAC address, the mac info will
be stored in to the ARP table of initiator system.
Let’s see some ARP tables,
root@sol-test-1:>/# arp -a
Net to Media Table: IPv4
Device IP Address Mask Flags
Phys Addr
------ -------------------- --------------- -------- ---------------
e1000g0 192.168.234.1
255.255.255.255
00:50:56:c0:00:08
e1000g0 sol-tst-2
255.255.255.255 o
00:0c:29:b4:6d:08
e1000g0 sol-test-1
255.255.255.255 SPLA
00:0c:29:c2:8f:90
e1000g0 192.168.234.139
255.255.255.255 o
00:0c:29:f3:2a:c7
e1000g0 192.168.234.206
255.255.255.255 SPLA
00:0c:29:c2:8f:90
e1000g0 192.168.234.211
255.255.255.255 SPLA
00:0c:29:c2:8f:90
e1000g0 192.168.234.209
255.255.255.255 SPLA 00:0c:29:c2:8f:90
e1000g0 224.0.0.0
240.0.0.0 SM 01:00:5e:00:00:00
sol-test-1 has details of almost all systems present on network,
root@sol-test-4:>/# arp -a
Net to Media Table: IPv4
Device IP Address Mask Flags
Phys Addr
------ -------------------- --------------- -------- ---------------
e1000g0 192.168.234.1
255.255.255.255
00:50:56:c0:00:08
e1000g0 192.168.234.133
255.255.255.255 o
00:0c:29:c2:8f:90
e1000g0 sol-test-4
255.255.255.255 SPLA
00:0c:29:89:b5:98
e1000g0 192.168.234.205
255.255.255.255 SPLA
00:0c:29:89:b5:98
e1000g0 224.0.0.0
240.0.0.0 SM 01:00:5e:00:00:00
sol-test-4 has less entries than previous one (sol-test-1), OK ….
Let’s ping a system and see does it modify its ARP table or not?
root@sol-test-4:>/# ping 192.168.234.134
192.168.234.134 is alive
root@sol-test-4:>/# arp -a
Net to Media Table: IPv4
Device IP Address Mask Flags
Phys Addr
------ -------------------- --------------- -------- ---------------
e1000g0 192.168.234.1
255.255.255.255
00:50:56:c0:00:08
e1000g0 192.168.234.134
255.255.255.255
00:0c:29:b4:6d:08
e1000g0 192.168.234.133 255.255.255.255
o 00:0c:29:c2:8f:90
e1000g0 sol-test-4
255.255.255.255 SPLA
00:0c:29:89:b5:98
e1000g0 192.168.234.205
255.255.255.255 SPLA
00:0c:29:89:b5:98
e1000g0 224.0.0.0
240.0.0.0 SM 01:00:5e:00:00:00
Now 192.168.234.134 is updated in ARP table of sol-test-4
This way ARP table is build,
What does the following field stand for?
Device IP Address Mask Flags
Phys Addr
Device Interface
of the system from which the system is connected to network
IP Addr The IP address or host name of
the system to which this entry applies
Mask This
indicates whether the entry refers to a host or the multicast address range
Flags S Static entry
P Published
entry, A system can be configured to advertise an ARP entry on behalf of
systems that cannot respond to ARP requests
M Mapped
entry. This is used for the 224.0.0.0 multicast entry only
U unresolved or incomplete entry
Phys Addr MAC
address for the entry
We can also add static
entries to ARP table,
#arp -s hostname ethernet_address
root@sol-tst-2:>/# arp -a |grep 200
Nothing in O/P,
root@sol-tst-2:>/#
arp -s rh-server 00:0c:29:f3:2a:bd
arp: rh-server:
unknown host
Add the entry of
rh-server to /etc/hosts
root@sol-tst-2:>/#
vi /etc/hosts
192.168.234.200
rh-server
wq!
root@sol-tst-2:>/#
arp -s rh-server 00:0c:29:f3:2a:bd
root@sol-tst-2:>/#
arp -a |grep rh
e1000g0
rh-server 255.255.255.255
S 00:0c:29:f3:2a:bd
RARP
Now I know MAC address
and I want to know IP from MAC
One of the Best
Example of RARP is While Jumpstart Installation
By default Open
Boot PROM (OBP) is configured to use RARP as the network boot strategy.
/etc/ethers
/etc/hosts
Supports MAC to IP
resolution, /etc/ethers does not present by default, it needs to be created “Created
on Boot Servers Only”
root@sol-test-1:>/#
cat /etc/ethers
00:0c:29:b4:6d:08
sol-tst-2
00:0c:29:89:b5:98
sol-test-4
DAEMON,
root@sol-test-1:>/#
svcs -a |grep -i rarp
disabled Dec_29
svc:/network/rarp:default
root@sol-test-1:>/#
svcadm restart svc:/network/rarp:default
root@sol-test-1:>/#
svcs -a |grep -i arp
online 19:12:32 svc:/network/rarp:default
root@sol-test-1:>/#
ps -ef |grep -i arp
root
5270 5204 0 19:15:25 pts/2 0:00 grep -i arp
root
5264 1 0 19:12:32 ? 0:00 /usr/sbin/in.rarpd –a
/usr/sbin/in.rarpd
is daemon
The in.rarpd
RARP daemon must be running on systems that provide RARP responses to requests
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