Network equipment hard core technology insider router Chapter 5 tompkinson roaming the network world (Part 1)

( This article is modeled on the American scientist George · Gaimov is here 《 Adventures in the physical world 》 Writing techniques in , Salute here )

Mr. tompkinson is an enterprise IT Administrators , Long term management of a large number of servers and storage devices . In his eyes , Network engineers are no different from a group of mysterious hackers . On the day , His colleagues in the network Department asked him to listen to a “ Next generation Internet technology ” The lecture of , He's on a whim , He promised to go .

The old professor on the podium is an academician of the Chinese Academy of Sciences , It's about industrial Internet 、5G and SDN The content of . Mr. tompkinson is hard to understand , The old professor's strong Cantonese accent Mandarin made Mr. tompkinson unable to understand . When the old professor said Segment Routing When , Tompkinson's upper eyelids are almost down his cheeks .

When Mr. tompkinson wakes up , He found himself in a crystal clear world , All sides are as bright as mirrors . He looked left and right , But I can't see other partners .

All of a sudden , He heard the voice behind him ：

“ Run ！ I'm going to hit your tail ！”

Mr. tompkinson hurried to run . This run can't stop , Mr. tompkinson found that the world around him seemed to have become slender .—— This is due to the relativistic effect .

Mr. tompkinson asked the voice behind him ：“ Who am I , Where are we ？”

“ We are in the optical fiber .” The voice behind answered .“ You are now a data frame in the computer network .”

“ Where am I from , Where to go ？” Mr. tompkinson seems to be thinking about profound philosophical issues .

“ Write your source address and destination address on yourself .” The voice behind me is impatient .“ You are an Ethernet packet , So from the first 14 Byte start , To the first 33 Bytes , yes IP Data packet head . who are you , Where are from , Where to go? , It's all written in it .”

Mr. tompkinson hasn't seen it yet , I found that the front became dark .

In front is a large gray black , Gray black with purplish red grid .

Mr. tompkinson plunged into the gray black .

He shouted around ：“ What is this place? ？”

At this time , Another voice answered him ：“ I am an oasis spirit . Mr. tompkinson , Welcome to the inside of the router .”

“ You are now entering the Ethernet of the router MAC chip ”. Oasis spirit introduced to Mr. Tompkins .“ You will be sent to the next station immediately .”

The voice of the oasis elves has not fallen , Mr. tompkinson seemed to be squeezed into the water slide , After the twists and turns , He sank into another gray black silicon chip . immediately , He slipped into a non-stop conveyor belt , Like the baggage carousel at the airport .

The oasis fairy told him ：“ Here is the memory of the router . You are a lucky packet .”

Mr. tompkinson asked ：“ Why do you say that ？”

“ this , It will start a long time ago .” Oasis fairy smile ：“ Of course , Too long stories are uninteresting .”

At this time , Mr. tompkinson was sent to a robot with a square head and a square brain . The robot looked at the QR code on Mr. tompkinson's coat , read ：

“ source address B4-AE-2B-E7-B9-CE, Destination address 24-69-68-B7-1C-EF, type 0x0800”.

“ The destination address is consistent with the network card , Next Station ,IP Forwarding process ”

then , The robot tore off Mr. tompkinson's coat in a hurry , With a pair of machines claw He took Mr. tompkinson to another conveyor belt .

Mr. tompkinson was sent to the next robot .

The robot looked at the QR code on tompkinson's shirt , read ：

“ source address 123.112.90.43, Destination address 75.126.33.156”.

here , The red and green lights on the robot's head flash wildly , A steel gray box behind him also clucked . Mr. tompkinson looked at the steel gray box , It's written in red ：TCAM.

The oasis elves seemed to understand what Mr. tompkinson was thinking , Whisper to him ：“ Mr. tompkinson , You may be in trouble ……”

“ ah ？” Mr. tompkinson's eyes widened .

To know what trouble Mr. tompkinson is in , Please look at the next breakdown .

Current issues ： If Mr. tompkinson's coat ( Ethernet head ) On , The type is not 0x0800, It is 0x8906, How will it get out of the router ？

Answer to the questions in the previous issue ： If a malicious attacker connects the attacking device to the network and sends OSPF LSA, Publishing should lead to other IP Routing of addresses , Interfere with the operation of routers in the network , How to avoid this attack ？

OSPF Support MD5 And other ways of router identity authentication , Routers that fail to pass the identity authentication cannot be established with other routers OSPF Neighborhood .