netmap

I. Netmap Introduction:1.netmap is a high-performance framework for sending and receiving raw packets, developed by people such as Luigi Rizzo, which contains kernel modules and user-State library functions. The goal is to achieve high-performance delivery of the data packets between the user state and the NIC without modifying the existing operating system software and requiring no special hardware support

Netmap to VALE-from high-performance network framework to High-Performance Virtual Network Switch, netmapvaleAs mentioned in the previous article, for full virtualization and semi-virtualization, a virtual network interface needs to be assigned to the virtual machine, which requires a vswitch (which can be used together with the hypervisor ), in this way, packets from virtual network interfaces are forwarded from physical interfaces. However, in compl

As I mentioned in the previous article, for full virtualization and para-virtualization, a virtual network interface that needs to be assigned to a virtual machine requires a virtual Switch vswitch (which can be used with hypervisor) to forward the packets from the virtual network interface to the physical interface. But in a complex system, the performance of this virtual switch is often not good. Open source project Netmap[1] made a high-performance

2, the same below), modify $/boot/sys/proc32-L 1 in install.2 to $/boot/sys/proc32-L 2, the following 2 is the node number. Generate a new imageCD/bootMake B = install.2CP images/install.2/. bootModify configuration fileCD/etc/configCP sysinit.1 sysinit.2CP inetd.1 inetd.2CD BinCP input.1 input.2CP ph.1 ph.2CP tcpip.1 tcpip.2Modify tcpip.2. The IP address is used. To use DHCP, comment out/usr/UCB/ifconfig EN1 10.1.1.119 node $ node up and replace it with/usr/UCB/DHCP. clientModify/. Licenses an

because of lack of resources. But in the field of high-frequency trading, we want certain processes to handle each message with fast response times, low latency fluctuations, and no need for the average performance of all processes on the machine.2. The TCP/IP protocol stack is optimized to prevent link loss and effective bandwidth utilization.There are already a lot of mature solutions available, and they are: Ntop.org DNA Netmap In

improve a large section, the basic can meet the requirements of 10G or even higher. But there are some drawbacks to such schemes: 1 User state needs to implement a simple protocol stack, to some extent, will increase the workload 2 The system robustness and security has a certain reduction. Users can access and control peripherals directly. System intrusion cost is too low, so it is not suitable for some open application scenarios. The second category is based on the kernel-driven optimization

First, the basic concept:1. ModuleThere are two types of modules in Python, one is a standard module, Python comes with a module, and the other is a third-party module that needs to be downloaded via Easy_install or PIP.The first week of learning the Getpass module is the standard module, through the import getpass can be calledTwo modules commonly used in System management, OS and SYS modules1) OS module:Os.system:　　　　　　>>>ImportOS>>> Os.system ('df-h') Filesystem Size Used Avail capacity iused

threshold, the qdisc stops sending, and the transmission is paused, preventing the packet loss on the data transfer kernel path , and the Qdisc continues to transmit when the TX queue is smaller than the threshold value. In this way, as long as the length of the Qdisc configuration appropriate, the internal transmission of the client must be lossless. Our architecture is based on virtio technology, so that the virtual adapter queue is also shared between the client operating system and the unde

preventing packet loss in the data transmission kernel path; when the TX queue is smaller than the threshold value, Qdisc will continue to be transmitted. In this way, as long as the length of Qdisc is properly configured, the internal transmission of this client must be lossless. Our architecture is based on virtio technology. In this way, the virtual adapter queue is shared between the client operating system and the underlying hypervisor. (This eliminates the need for an additional copy :)).

and the transmission will be paused, thus preventing packet loss in the data transmission kernel path; when the TX queue is smaller than the threshold value, Qdisc will continue to be transmitted. In this way, as long as the length of Qdisc is properly configured, the internal transmission of this client must be lossless. Our architecture is based on virtio technology. In this way, the virtual adapter queue is shared between the client operating system and the underlying hypervisor. (This elimi

According to the spirit of attending the OPCs meeting-"Other people's conferences", the meeting is not about the demographic/professional group, but where you are invited-I am currently attending the Microsoft Research Institute Summit. I'm not a computer scientist, I'm not a college teacher, I have not done any research funded by Microsoft ..., but all of this is so reasonable and enjoyable, because it is a very interesting gathering to find research topics in the field of computer research, wi

:apple_boot Recovery HD 650.0 MB disk0s3/dev/disk1 (internal, virtual):#: TYPE NAME SIZE IDENTIFIER0:APPLE_HFS Macintosh HD +120.1 GB Disk1Logical Volume on Disk0s2E16f3c8b-2351-4f73-ad20-88a4479124e8Unlocked Encrypted/dev/disk2 (external, physical):#: TYPE NAME SIZE IDENTIFIER0:fdisk_partition_scheme *7.9 GB Disk21:0xef 6.4 MB Disk2s2mewdemacbook-pro:~ mew$ df-hFilesystem Size used Avail capacity iused ifree%iused mounted on/dev/disk1 112Gi 53Gi 59Gi 48% 13837631 15485631 47%/Devfs 183Ki 183Ki

the total number of blocks used on each available volume and the percentage of free space. 　　Listing 6. determine the volume usage $ dfFilesystem 512-blocks Used Available Capacity Mounted on/dev/disk0s2 311909984 267275264 44122720 86% /devfs 224 224 0 100% /devfdesc 2 2 0 100% /devmap -hosts

"Time" match support "Iprange" match support "Connlimit" match support "State" match support "Conntrack" connection matchsupport "Mac" address match support "Multiport" Multiple port match support Networking support → Networking Options → Network packetfilter

address.If I try to browse the web on victim-laptop, I am served the resource matching the rules in hacker-laptop ~~â ?~~~~~~~~~~~~â s web server.That means all of the non-HTTP traffic associated with viewing a web page still happens as normal. in particle, when hacker-laptop gets the DNS resolution requests for Google.com, the test site I visited, it will follow its routing rules and forward them to the real router, which will send them out to the Internet:The fact is that hacker-laptop has re

the package between XEN and guest OS, although this requires receiving buffers of the guest OS to queue at the network interface. After receiving the packet, the XEN will quickly query the rules to determine the corresponding vif, and exchange the packet with the packet buffer of the page frame on the receiving ring. "If no frame is available, the packet is dropped. "Therefore, packet loss is likely to occur during the receiving process. That is to say, if the receiving ring is full, packet los

interface used to accept data packets forwarded through a local route or sent to the host's inbound interface. in OUTPUT, DNAT and REDIRECT rules are used to process outbound data packets generated by the NAT host. SNAT eg: Iptables-t nat-I POSTROUTING-s10.1.0.0/24-j SNAT -- to-source 192.168.0.5 Map Intranet 10.1 fields to 192.168.0.5 You can also do this: Iptables-t nat-I POSTROUTING-s10.1.0.0/24-j SNAT -- to-source192.168.0.5-192.168.0.245 Map a local IP address to an IP address (attack can

, UDP is a novel direction. If you have expectations for the underlying transmission protocol in the future: Custom protocols appear in the user space (User core), similar to QUIC Traditional TCP/UDP can run in user space and directly skip the kernel The complete protocol stack is provided to upper-layer applications in the form of a static Link Library Upper-layer applications can include the so files of their dependent protocol stack static Link Library during compilation and packaging.

guest OS's receive buffers to queue at the network interface. When the package is received, Xen will quickly query the rules to determine the corresponding vif, and swap the packet with the packet buffer of the page frame on the receiving ring."If no frame is available,the packet is dropped. "So it is possible to lose packets during the reception process, which means that if the receiving ring is full, then the packet is dropped."Note that this talk is similar to

content SNAT is generally used to access the Internet. DNAT is used to come in from outside SNAT eg: Iptables-t nat-I POSTROUTING-s 10.1.0.0/24-j SNAT -- to-source 192.168.0.5 Map Intranet 10.1 fields to 192.168.0.5 You can also do this: Iptables-t nat-I POSTROUTING-s 10.1.0.0/24-j SNAT -- to-source 192.168.0.5-192.168.0.245 Map a local IP address to an IP address (attack can be performed ^) The same function in the preceding example: iptables-t nat-I POSTROUTING-s 10.1.0.0/24-j