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The detailed difference between 4G industrial router...   4G industrial router and 4G DTU both realize the wireless network data transmission function, and the differences between them are mainly from the use method, appearance interface and application environment, etc. Today, we will introduce some differences between 4G router and 4G DTU.   Different methods...

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Application analysis of iot sensing technology   The Internet of things (iot) is widely used in the integration of networks through intelligent perception, recognition technology, pervasive computing and other communication perception technologies. The iot is understood as "Internet connected by things". The Internet of things (iot) connects all objects with...

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What is a single/dual frequency wireless 4G router 1. Introduction to "single frequency" router The single-frequency router only works in the 2.4ghz band, which is generally supported by wireless terminals. However, the 2.4ghz band has large interference, which may affect the wireless rate and stability.   2. Introduction to "dual-frequency" router Dual-frequency...

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Wireless communication DTU features Data Transfer unit (DTU) is a wireless terminal device specially used to convert serial Data into IP Data or convert IP Data into serial Data for transmission through wireless communication network.   DTU advantages: Rapid and flexible network, short construction cycle, low cost; Wide network coverage; Good...

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The advantage of using wireless data transmission module... Data transmission can be simply divided into two major types: wired (including the installation of optical cables, cables or leased telecommunication lines) and wireless (including the establishment of dedicated wireless data transmission system or the borrowing of CDPD, GSM, CDMA and other public network information platforms).     In...

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了解工业级路由器Classless与Classful路由协议

文章目录 : 产品文章

大家都非常清楚,可以将一个IP网段划分成多个子网,子网的掩码可以是任意位数,比如将一个10.0.0.0/8的大网划分出10.1.1.0/24,10.1.2.0/24,10.1.3.0/24等等,划分出来的更小的网络叫做子网,而原来的大网络叫主网,也称为主类网络,A类地址掩码必须为8位才是主类网络,B类地址掩码必须为16位才是主类网络,C类地址掩码必须为24位才是主类网络。

无论是主网还是子网,都会被工业路由器放入路由表,只是某些工业LTE路由器路由协议不能精确传递子网而已,但只要路由协议传递了子网和掩码,工业级路由器就一定会将其放入路由表中。

支持子网的功能被称为Classless,支持Classless可以与子网很好的协作,如果不支持子网,则被称为Classful,所以,一个路由协议是工作在Classless还是Classful,直接关系到全网路由器路由信息中是否存在精确的子网信息,如RIP和EIGRP,并且这些功能可以在协议中手工开启或关闭。4g DTU

路由协议有Classless与Classful的说法,而IOS本身也有运行在Classless还是Classful的说法,IOS是工作在Classless还是Classful,并不影响路由表中是否有子网条目,也就是说,IOS工作在Classless还是Classful,并不影响工业3G路由器路由表的建立,工业级LTE路由器路由表不会有任何区别,但是,Classless与Classful会决定工业无线路由器转发数据包的进程,影响如下:

对于某个主类网络,如10.0.0.0/8,当工业全网通路由器路由表中存在其中部分子网,如10.1.1.0/24和10.1.2.0/24,当工作在Classless时,对于已经知道的子网,工业级无线路由器会将数据包精确地发送到相应出口,而对于并不知道的子网和其它所有未知目标网络,如10.1.3.0/24和30.1.1.0/24,如果存在默认路由的话,工业级4G路由器便将他们全部发送到默认路由所指示的出口;但是当全网通路由器工作在Classful时,工业级全网通路由器知道了子网10.1.1.0/24,就始终会认为其它所有10.0.0.0/8范围内的子网都应该真实存在于网络中,会认为10.1.2.0/24、10.1.3.0/24等等都存在于网络中,只是自己没有详细路由,这时,当路由器收到去往10.1.1.0/24的数据包时,可以正常转发,但是如果收到去往10.1.3.0/24和30.1.1.0/24的数据包,当路由表中存在默认路由时,去往30.1.1.0/24的数据包会被发送到默认工业级3G路由器路由指示的出口,而去往10.0.0.0/8中的未知子网10.1.3.0/24的数据包则被全部丢弃而不走默认路由。

由以上情况可以看出,工业4G路由器工作在Classful时,如果知道了某个主类网络中的部分子网后,其它所有未知子网的数据包将被全部丢弃而不转发,即使存在默认路由,也不会转发,而其它主类网络的数据包还是会正常转发。IOS的Classless与Classful可以通过命令ip classless和no ip classless开启或关闭。

标签:4g路由器   无线路由器

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