s******r
发帖数: 868 | 1 5个月 前和verizon签的两年，签的时候，从iphone switch到了LG G2，各种不爽，现
在发现sprint有这个pay to switch，貌似不错，如果我early terminate 现在verizon
的罚300，sprint最高可以pay 350,所以应该可以cover，就是不知道具体如何操作，有
没有人这样干过啊 |
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s********1
发帖数: 581 | 2 家里建网应用router还是switch?
家里正在建网络，DSL modem 只有4个出口，现在打算在加两个，不知哪种选择既好又
便宜？
(1)买一个新的8个出口的DSL modem(DSL router)，不知不同型号的modem有什么差别？
另外
(2)买一个4个出口的router接在DSL modem的其中一个出口上,一共7个用户出口
(3)买一个4个出口的switch接在DSL modem的其中一个出口上,一共7个用户出口
另外方案(2)和(3)，不同用户的上网速度会有差别吗？
谢谢 |
|
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L******t
发帖数: 1985 | 4 It's called port-based authentication because 802.1x is originally designed
for wireless access in which a port is a user.
But technically speaking mac-based 802.1x is no difficultier than port-based
802.1x at all. I'm not sure if Cisco's Catalyst switches don't support mac-
based. Even that's the case, I believe the reason being even Catalyst
desktop switches are designed for one port per user. So I guess it's easier
to find mac-based feature on lower-end vendors.
Just googled "mac based 802.1x |
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L******t
发帖数: 1985 | 5 http://gigaom.com/2007/11/18/google-making-its-own-10gig-switches/
Google, has been known to come up with its own technologies when
dissatisfied with commercial and/or open source offerings. The company had
previously started making its own server hardware. And now it seems the
company engineers are building high-speed switches according to its own
stringent specifications. It is part of company’s efforts to ensure that
its services - search, advertising and everything else - are delivered to
e |
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c*****i
发帖数: 631 | 6 方向不一样，google的switch好像就是一个单纯的switch，它把很多intellege的part
放在它的server上了。它的server有跑软件可以知道整个network topo。好像这也是
Crowd Computing发展的另外一个方向把。好像当初做nexus 5000的时候就是瞄准
google的，不过google不满意，就自己做了。 |
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m********r
发帖数: 543 | 7 不提sonet，就算有10G, 100G interface的router 我觉得他们都搞不出来，那个不止
是port要有Line rate的speed, 后面的背板和fabric都要跟上。 至于1g的switch，外
面的vendor多如牛毛，而且google现在complain的就是现有的任何产品都不够他们的
流量，所以1g的siwtch或者router，不是他们想要的。
No need for SONET. Ethernet only switching.
They don't need to support that many fancy stuffs. So either buy off-the-
shelf NP or design their own, is doable.
packet |
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z**r
发帖数: 17771 | 8
this is quite normal for modern switch, something similar to Cisco TCAM?
sounds like IPS? or P2P traffic management?
why this can lower the cost? to me it looks like it would make the switch
more expensive? |
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m********r
发帖数: 543 | 9 啥叫打开feature不能line rate? ADPC就是40G的line rate.
只能在QDPC上开oversubscribe的qos, feature
如果我没搞错cisco的product的话, nexus做的是data center的switch, 和mx960
router没有可比性. 要比, 等着明年初j的data center switch出来比吧
那么多cisco不同的产品, 又是76000, 又是ASR, 又是NEXUS的, os都不同, CLI都不一
样, 你们这些ISP NOC admin烦不烦啊? oops, 好像只有sprint一家顽固地卖力不断使
用cisco的新产品了吧. CRS-1都进不了其他两家的ng network了
feature
40port |
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B*****R
发帖数: 1539 | 10 其实有什么区别，现在还有不RUN路油的SWITCH？那肯定是白菜 already
Switch |
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w***s
发帖数: 321 | 11 那么要做的是那种？rack switch, agg/core switch还是multi-chassis router? 抑或
以上皆是？ |
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w***s
发帖数: 321 | 12 那就还是偏向rack/core switch，既然10G NIC也不算罕见。
就看会不会出来个Multi-Chassis Switch了。
if
they |
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e**********w
发帖数: 117 | 13 什么下场就是送人？ NYSE交易所现在用的就是EX switch好不好，套个广告词，帮助了
NYSE实现了fast trading，有么有觉得最近炒股少吃一点spread的亏？ xixi
言归正传，你还是眼睛蛮尖的，都看出来了“EX并不完全是所谓的硬件switching，起
码在早期出货的低端EX上不是这样的，主要工作由控制层上的PowerPC来通过软件实现
”。 便宜没好货，要好货买更贵的MX吧。。。 //run
Availability |
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j*a
发帖数: 14423 | 14 check dst mac.
if dst mac belongs to switch then route, otherwise switch. |
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s*********4
发帖数: 1980 | 15 简单说,应该是速度和效率吧.参考CISCO的multilayer switching with Content
Express Forwarding (CEF)可以展开来回答这个问题.用于layer 2 switching的
Forward Information Base table建立于layer 3的routing table基础上.Layer 2处理
不了的某些类packets可以立刻转给Layer 3的Engine处理等等. |
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T********i
发帖数: 2416 | 16 我的要求是延迟越低越好。
现在我的合作公司提供的是CISCO 6509-V-X。据说是两年前买的。他们声称处理
multicast比
4900m要好。
个人感觉不太靠谱。当然我有机会自己买一个switch，Blade或者Arista，$10,000出头
，号称
Latency 600-700ns，可以说服他们把我的switch挂在前端。
如有人知晓CISCO 6509-V-X的内幕，望不吝赐教latency的范围。 |
|
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s*****g
发帖数: 1055 | 18 It is not because Cisco Switch 烂, it is because competitor's products are
as good (or slightly better in some aspects and inferior in some other
aspects). But the days when others could not make the same switch so Cisco
could charge customers premium are long gone. Customers are no stupid. |
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w*f
发帖数: 111 | 19 I work for a financial firm
1. Catalyst 6500 is still the one for access switches and distribution
switches
2. Nexus is a better platform for datacenter core
3. Juniper is making progress in larger enterprise where a bigger IT group
can support another vendor |
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s******v
发帖数: 4495 | 20 As I said in previous posts, not only the margin, but CSCO lost about
200+M switch revenue in last Q, even you consider the increase of data
center switch.
the deteriorated relationship with other system integrators contributes
largely to this drag down.
Nexus |
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s******v
发帖数: 4495 | 21 from what i learned recently, the n7k is not a direct replacement of
cat6k. the 1st one is flat data center switch, the 2nd one is the
traditional campus switch.
but be frank, i am not very clear about the difference of these 2
different product catergories. just know the 3-tier of network
architecture is not a good fit for today data center, now they like to
implmented flat and low latency topology.
this is a good example that, when the underlying requirements changes,
it shifts the dynamics of... 阅读全帖 |
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b******a
发帖数: 153 | 22 Juniper does not show the switching side problem because its switching is
almost from 0 to whatever. Cisco is
from whatever to less. Base is totally different. HP is cap on its servers
and eating server access ports which is
very dangerous competitor to anybody else in industry.
IT still driven by Cost reduction and Business Value. Nexus has very good
architecture to reduce IT cost by
converging storage and data into one - Ethernet. Cisco needs time to educate
CIO/CTO on that. It is huge
saving ... 阅读全帖 |
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B*****R
发帖数: 1539 | 23 you mean juniper switch does not have a play or they don't want to play..
both verizon and NYSE have bot large number of ex82 switches. juniper is
quite serious |
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x*********n
发帖数: 28013 | 24 好吧，我什么都不懂。
你怎么想的，无所谓，反正知识是你自己的，器材你想怎么接也无所谓，SFP是啥，
RJ45,100M，200M，1G都可以，谁来在乎你怎么错啊。
设备你看cisco。com就会发现了，2960是access layer的，3745是之类的是
distribution layer，6500之类的是core layer。
access port是接workstation，uplink是接switch，uplink之所以要大一点，是因为
data都要从这里过。
BTW，以后你的帖我就不回了，省的你生气。说实话我也有点生气，自己的说的被人无
视了，呵呵。
BTW，芝加哥的fanacial company都是直接杀鸡用牛刀的，整幢楼用的是一个型号的
switch，据说，为了以后容易搬家，train员工方便。便于管理。。哈哈哈。。财大气
粗没办法啊。 |
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f*******8
发帖数: 3612 | 25 怎么不直接回答我的问题:)
我感到有几个问题，一个是Hub和switch这些词在早期是不是用的混乱，俺不太清楚，
再一个，hub是不是也有一定的进化，从最早的单纯无任何记忆的转发，
到后来可以记忆一定的MAC，然后再进化到现代的switch.这个历史也不清楚。Hehe |
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x*********n
发帖数: 28013 | 26 topology当然要这么画啦。你看cisco解释STP的时候，画的都是bridge，用的时候还是
switch啊。
早就和你说了，campus网络里面除了switch router，最多加一个firewall，别的找来
干嘛？ |
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Q*******e
发帖数: 939 | 27 What's DC Switch?
What's feature DC Switch must have? |
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f*******8
发帖数: 3612 | 28 好像有些公司用3750 stack, 我看了一下，没领会这个结构到底有什么应用上的不可或
缺的优点。
1 能理解它在管理上有单一的IP等等，所以好管理，但这个特点，只要switch不是太多
，不用stack也可以。
2. 从end user(就是每个port接的用户）角度来讲，你switch是stack起来也好，是其他
方法连接起来也好，只要能连起来，特性有什么差别么？
3. 用vtp不是也可以集中配置么？
stack 有什么不可替代的地方么？
--------------
人生还能怎么样？人生就是一连串的现象，所有现象，无非所见。
Be Careful what you wish for; it may come true. |
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x*********n
发帖数: 28013 | 29 port channel不能跨switch 是啥意思啊？
port channel不是都是2个switch之间连着的么？ |
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a****8
发帖数: 2771 | 30 一个4端口的port channel, 两个在一个switch上，两个在另一个switch上。 |
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s******v
发帖数: 4495 | 31 这个好像挺hot的，想学习一下，refresh一下knowledge。
这个DC switch和过去的switch有什么不同吗？除了
1）三层变成两层；
2）latency低
好像各家的技术也不一样，有没有入门的document，大家share一下，多谢！ |
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s******v
发帖数: 4495 | 32 这个好像挺hot的，想学习一下，refresh一下knowledge。
这个DC switch和过去的switch有什么不同吗？除了
1）三层变成两层；
2）latency低
好像各家的技术也不一样，有没有入门的document，大家share一下，多谢！ |
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m**t
发帖数: 1292 | 33 设计时候忘了，以为已经是 switch 了，还要 switch 干什么 |
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p*****s
发帖数: 344 | 34 no magic to me. if the linux os is to be the controller for the 640G switch
the bottle neck is still there. no matter how many application it can run it
won't scale. you either get a flexible 10G flexible application router or a
100G baremetal switch, can not get both without special hardware. |
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s*****g
发帖数: 1055 | 35 Cumulus to Dell is like Microsoft/Redhat to Dell, Cumulus does not make
switches, it makes software and the software runs on Dell hardware.
Can Arista switch run OS of my choice? can I build my own software package
and run the software on it? granted, all vendors can provide feature sets
Cumulus can not match (at least for now), but how much percentage of those
features are needed by you? |
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m**k
发帖数: 290 | 36 This is not new. Many switch vendors run linux in their box.
The main difference is price. And the reason for higher price of most
vendors is they have too many bad software engineers.
To network engineers, the difference is whether to expose linux commands to
the user or to have a unified cli. People have different preferences, and
most cli sucks.
Also, linux support for network device (routing/switching) is not very good.
There are still a lot of work to be done. |
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w*f
发帖数: 111 | 37 OpenSource does not mean it's good quality. Network hardware running Linux
does not make it good quality network gear. As a customer, good tech support
and features must be considered by looking at $
If I am a Wall Street trader, do I care "my order is carried by Cisco switch
, or white box switches running Linux"?
He needs networking to be stable and quick. |
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d****i
发帖数: 1038 | 38 actually one of the major concern of this CVE is for routers/switches, where
the upgrade/patch is not so easy as servers, especially for those routers/
switches that have enabled some web services for management/configuration
etc, which are more and more popular. |
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I********x
发帖数: 858 | 39 you can run GNS IOS for routers, but the switch is not good in GNS.
switch |
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r*******i
发帖数: 1640 | 40 我知道楼里有人在用switch的，用了他们的switch也不行，他们说也没怎么设置过。。 |
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p**i
发帖数: 688 | 41 你的两台机器插不同宿舍的port能同时上网吗, 如果可以
你们宿舍网络的switch比较高级, 可以有per port的MAC限制
你可以考虑加个网卡到台式机上, 然后该网卡连你的switch |
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w****a
发帖数: 186 | 42 多谢各位的指教，但问题还是没解决。
我把switch连到另外一个wall plug上，电脑能申到IP、能连上网，所以switch应该没
有问题。我也拿了个原来用的router连到这个有问题的wall plug上，也是找不到IP。
更奇怪的事情是我的笔记本电脑能通过这个wall plug上网，但是我的台式机不能。
我也试过了正常的网线和交叉的网线，没有什么区别。
我现在怀疑这个wall plug有接触的问题，或者是电阻不正常？导致某些网络设备能连
，某些不能连。我没用过cable tester，如果用tester的话，能检查这种情况吗？尤其
是要检查一头是线，一头是插座的情况，cable tester能管用吗？谁有这方面的经验呢？
多谢了！ |
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t****t
发帖数: 6806 | 43 用flood ping看看丢不丢包. 有些便宜的switch会丢包, 这个很影响千兆网的网速.
使用了TRENDnet Gigabit GREENnet switch，上下传只能到1MB，差不多相差10倍，为
什么啊？网线都用的是普通Cat5，电脑是百兆网卡，NAS是千兆网卡。
啊。 |
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e**t
发帖数: 83 | 44 这个我知道。我只要能到百兆网的速度就可以了。问题是用了千兆switch，速度比百兆
switch慢很多。
测试速度拷的文件都是2G以上的大文件。 |
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w***w
发帖数: 1552 | 45 这个switch还不错啊。
俺的是pc1-router-siwtch-nas，router是n16，主要是switch到pc1的那根网线杯具只能
上百兆。估计过个router速度会降些，虽然号称是giga口
硬盘 |
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e**t
发帖数: 83 | 46 前面说错了，应该是下传10MB，上传很慢只有2-3MB，笔记本和NAS都是千兆网卡。
如果用desktop直接连switch，上下传都很慢（远不到10MB）。台式机连router->
switch->NAS，下传快些，上传一样慢。 |
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e**t
发帖数: 83 | 47 pc <--> router <--> switch <--> nas，从nas读比直接连switch要快一些，但也没到
10MB，写入NAS的话基本一样慢。 |
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k****t
发帖数: 2288 | 48 网上查了一下当时的invoice，
不是打广告哦~~
我的switch的型号是： Netgear GS105NA Giga Switch 5Pt Metal |
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y*****n
发帖数: 11251 | 49 关键问题是你一楼router 的wan 怎么连到二楼的switch。选项就这么几种：
1. wireless bridge. 直接wireless连到二楼的router
2. powerline ethernet. 需要检查是不是通过electric switch box.
3. 直接用cat5/6 线。
cable
router, |
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a*o
发帖数: 19981 | 50 有木有兄弟想要个48 port千兆switch的？哥有个这个不想要了：
http://www.amazon.com/Prosafe-48-PORT-Gig-Mngd-Switc/dp/B0036RF
其中8个port throughput不稳定我都用mark笔标了，40个port是完全健康的。
fully managed，支持vlan，QoS等等各种fancy的功能。cli很接近cisco IOS style，
有不错的web management界面。
48个port全是千兆，不是很多号称gigabit switch其实只有很少几个千兆，其它port都
是10/100。最后4个口还可以接fibre，不过我没有卡和线去测试，就不知道啥状态了。
有意者PM我，随便给个价。。。 |
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