IPv6 - Basic Introduction

Hi , As we all know IPv6 is on its way to enter in our life. Why I am saying life ..?

Since in one year it is planned to implement in India and hopefully I know its same situation everywhere.


India's Internet Gateway and all Service provider is all equipped and ready with IPv6 Internet services. 

As right now we are using so many devices, Which are taking us on Internet like Mobile, Laptop, PC, Pads,etc. But we don't have enough IP addresses for usage. 

Right now major IPV4 addresses are allocated to U.S.  So as we need addresses, we don't have any other option than IPv6.

First a brief , Why we want IPv6 address ?

Right now we are facing severe shortage of public IP address, every device wants a public IP address to go on internet. Till now we are using NAT to survive or we can say to extend life of IPv4.  Otherwise IPv4 was suppose to expire years before.

Current Network Limitation with IPv4 Addresses - 

• Shortage of Public IP addresses.
• Mobility is limited.
• New devices are lacking with IP address.
•  Management issues.
• IPv4 lacks scalability due to 4.4bn addresses. Major address pools are allocated to US.

Everybody is looking positively for IPv6 deployments. Since it’s our future …

Let’s see some Goals and Benefits of IPv6.

Goals -

•  Every Network device should have Public IP address to use Internet.
•  As we have public network, we can have IPSec and secure communication across Networks.
• Mobility – In IPv6 we have tons of address, That means every Mobile devices will have Public address for communications.
• IPv6 major target is to eliminate NAT.

Benefits –

• IPv6 comprises of 128 bit address as compared to IPv4 32 bit address space.
• It is having 3.4 x 10³⁸ address, which is more than enough.
• IPv6 is having very simpler header as compared to IPv4 header. If you compare size of header, its more than IPV4. But right now bandwidth is not issue or our concerns.
• IPv6 has less fields in header, It will help to improve Router CPU performance as compared to IPv4 complex header. Which is CPU intense. 
• As IPv6 header is simple, with less fields. So, Its very secure as compared to IPv4. 
• In IPv6 apart from basic header, we have extension headers. Which will be used as per requirements.  For example a mobile node adds mobility related extension headers to its outgoing traffic.
• IPv6 don’t have broadcast. Now in IPv6 everything will majorly work on Multicast.
• ARP has been replaced with ICMP ND (Network discovery).
• IPv6 will improve routing – Aggregated Routing entries are created to reduce Routing table sizes.

I just started making study notes on IPv6, So In upcoming post I will share more about IPv6.

Hope this post is informative for you.

Thanks for reading. For feedback and likes, Plz comment with Name and mail id, New users can use Name/URL option.

Serial Link Troubleshooting - Maipu

Today I was troubleshooting one case, Maipu router as CPE with last mile as Serial link.

 As we all know, serial interface configuration is not complicated.

Below is standard configuration for serial interface in Maipu routers.

interface serial0/0

 physical-layer sync

 encapsulation ppp

ip address  x.x.x.x 255.255.255.252

exit

As router is DTE device, no need to configure clock rate under serial interface.

Then also the line protocol was not coming up. After debugging the interface, I didn’t find any IPCP events.

After analysis of debugging logs we got to know, The peer router is  not sending IPCP packets to Maipu router.

So in show output we cannot see destination address, it is showing 0.0.0.0

serial0/0:

     line protocol is down

     Flags: (0x80f0) POINT-TO-POINT MULTICAST RUNNING

     Type: PPP

     Internet address: x.x.x.x/30

     Destination Internet address: 0.0.0.0

     Queue strategy: FIFO , Output queue: 0/16 (current/max packets)(0)

     Metric: 0, MTU: 1500, BW: 128 Kbps, DLY: 20000 usec, VRF: global

     Reliability 255/255, Txload 1/255, Rxload 1/255

     5 minutes input rate 0 bits/sec, 0 packets/sec

     5 minutes output rate 0 bits/sec, 0 packets/sec

     0 packets received; 41 packets sent

     0 multicast packets received

     0 multicast packets sent

     0 input errors; 0 output errors

     0 collisions; 0 dropped

      LCP:REQUEST SENT

      encap-type: simply PPP

rxFrames: 3, rxChars: 54

txFrames: 438, txChars: 5894

rxNoOctet: 39, rxAbtErrs: 1, rxCrcErrs: 13

rxOverrun: 0, rxLenErrs: 38015188, txUnderrun: 0

DCD=up  DSR=up  DTR=up  RTS=up  CTS=up  TxC=up

Rate = 2000000 bps

As you can see the last status in bold is up. That means majorly no problem from our end.

Below is description for status –

DCD: INPUT/OUTPUT, the carrier detection signal.

DSR: INPUT, the data service request signal, input by the peer DTR.

DTR: OUTPUT, the terminal device is ready; output the DSR to the peer Side.

RTS: OUTPUT, the sending signals of the request data; output the CTS to the peer side, used for the hard flow control.

CTS: INPUT, allows the data sending signals, input from the peer RTS, used for hard flow control.

TxC: INPUT, the data sending clock. In DTE mode, it is input from the outside ,in DCE mode, generated by itself.

After this output, I added one command to configure manual IPCP peer under serial interface. Then it started working.

Below is working configuration –

interface serial0/0

 physical-layer sync

 encapsulation ppp

ip address  10.1.1.1 255.255.255.252

peer default address  10.1.1.2

exit

In future you face any time such issue you can try this command in Maipu routers for serial troubleshooting.

Hope this post is informative for you.

For any feedback, Plz comment with your Name and Mail id. New users can use
Name/URL option.

Thanks for reading…