What 'ge' 'le' really means ?
Hi all, In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 24 % Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25
we see 'ge' means greater. But in doc:
ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones
Simon, If you're trying to specify a maximum prefix length of 32, you need the le keyword. ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 means "accept any prefix length for 192.18.8.0 between 24 and 32 bits" IE ip prefix-list test_ipv4_1_1 seq 10 permit <subnet>/<shortest prefix match> le <longest prefix match> On Sat, Feb 15, 2020 at 5:47 PM Simon Jones <batmanustc@gmail.com> wrote:
Hi all,
In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 24 % Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25
we see 'ge' means greater.
But in doc:
ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
typo in my reply. When I said ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 I meant ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 le 32 On Sun, Feb 16, 2020 at 2:35 AM Daniel Corbe <daniel@corbe.net> wrote:
Simon,
If you're trying to specify a maximum prefix length of 32, you need the le keyword.
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 means "accept any prefix length for 192.18.8.0 between 24 and 32 bits"
IE ip prefix-list test_ipv4_1_1 seq 10 permit <subnet>/<shortest prefix match> le <longest prefix match>
On Sat, Feb 15, 2020 at 5:47 PM Simon Jones <batmanustc@gmail.com> wrote:
Hi all,
In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 24 % Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25
we see 'ge' means greater.
But in doc:
ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
Oh, thanks, so in summary: If I want to match 192.18.8.1/16 to 192.18.8.1/24, I use ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/ <http://192.18.8.0/24>16 le 24 If I want to match 192.18.8.1/24 to 192.18.8.1/32, I use ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/ <http://192.18.8.0/24>24 le 32 If I want to NOT match 192.18.8.1/16 to 192.18.8.1/24, I use ip prefix-list test_ipv4_1_1 seq 10 deny 192.18.8.0/ <http://192.18.8.0/24>16 le 24 Is that correct? But, what is 'ge' used for ... ? ---- Simon Jones Daniel Corbe <daniel@corbe.net> 于2020年2月16日周日 下午3:36写道：
typo in my reply. When I said ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 I meant ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 le 32
On Sun, Feb 16, 2020 at 2:35 AM Daniel Corbe <daniel@corbe.net> wrote:
Simon,
If you're trying to specify a maximum prefix length of 32, you need the le keyword.
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 means "accept any prefix length for 192.18.8.0 between 24 and 32 bits"
IE ip prefix-list test_ipv4_1_1 seq 10 permit <subnet>/<shortest prefix match> le <longest prefix match>
On Sat, Feb 15, 2020 at 5:47 PM Simon Jones <batmanustc@gmail.com>
wrote:
Hi all,
In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit
192.18.8.0/24 ge 24
% Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25
we see 'ge' means greater.
But in doc:
ge command specifies prefix length. The prefix list will be applied
if the
prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
The ge keyword exists so you can poke range holes in a larger subnet. For example: ip prefix-list test_ipv4_1_1 seq 10 deny 192.18.8.0/16 ge 24 le 30 Will match against IP addresses anywhere in 192.18.8.0/16 as long as the advertised prefix is between 24 and 30 bits long. On Wed, Feb 19, 2020 at 8:53 PM Simon Jones <batmanustc@gmail.com> wrote:
Oh, thanks, so in summary:
If I want to match 192.18.8.1/16 to 192.18.8.1/24, I use ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/16 le 24
If I want to match 192.18.8.1/24 to 192.18.8.1/32, I use ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 le 32
If I want to NOT match 192.18.8.1/16 to 192.18.8.1/24, I use ip prefix-list test_ipv4_1_1 seq 10 deny 192.18.8.0/16 le 24
Is that correct?
But, what is 'ge' used for ... ?
---- Simon Jones
Daniel Corbe <daniel@corbe.net> 于2020年2月16日周日 下午3:36写道：
typo in my reply. When I said ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 I meant ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 le 32
On Sun, Feb 16, 2020 at 2:35 AM Daniel Corbe <daniel@corbe.net> wrote:
Simon,
If you're trying to specify a maximum prefix length of 32, you need the le keyword.
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 means "accept any prefix length for 192.18.8.0 between 24 and 32 bits"
IE ip prefix-list test_ipv4_1_1 seq 10 permit <subnet>/<shortest prefix match> le <longest prefix match>
On Sat, Feb 15, 2020 at 5:47 PM Simon Jones <batmanustc@gmail.com> wrote:
Hi all,
In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 24 % Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25
we see 'ge' means greater.
But in doc:
ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
It's counter-intuitive. ge 24 means: /8 /16 /13 /23 etc. le 24 or 'less than or equal' means all CINR values that are numerically BIGGER. /24 /28 /32 /28 etc. So why 'le' and 'ge'? Because a /22 (1024 ips) defines a LARGER network than a /30 (only 4 ips) Where did all this math come from? What are bits? Let's take 4.2.2.0/24 as an example: The Mask or /24 value states how many bits in the IP address define the network. If your mask is 24 bits, and all IPv4 addresses is 32 bits (or 2^32) then the number of IPs in your network is: 2^ (32 - 24) = 2 ^ 8 = 256 Here is a list that filters all BGP prefixes that are for tiny blocks of IPs... you can limit your BGP session to only allow blocks that have a minimum of 256 IPs. In other words, anything "equal to or Greater" than 256 IPs: ip prefix-list bgpFilter seq 10 permit 0.0.0.0/0 ge 24 ip prefix-list bgpFilter seq 99 deny any Hope that helps, Rudy On 2/15/20 11:36 PM, Daniel Corbe wrote:
typo in my reply. When I said ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 I meant ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 le 32
On Sun, Feb 16, 2020 at 2:35 AM Daniel Corbe <daniel@corbe.net> wrote:
Simon,
If you're trying to specify a maximum prefix length of 32, you need the le keyword.
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 32 means "accept any prefix length for 192.18.8.0 between 24 and 32 bits"
IE ip prefix-list test_ipv4_1_1 seq 10 permit <subnet>/<shortest prefix match> le <longest prefix match>
On Sat, Feb 15, 2020 at 5:47 PM Simon Jones <batmanustc@gmail.com> wrote:
Hi all,
In this command:
gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 24 % Invalid prefix range for 192.18.8.0/24, make sure: len < ge-value <= le-value gyw-229(config)# ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/24 ge 25 we see 'ge' means greater.
But in doc:
ge command specifies prefix length. The prefix list will be applied if the prefix length is greater than or equal to the ge prefix length
So what's 'ge' really means? And how to set equal command? Set equal command using 'ge xxx le xxx' before, but if 'ge' means greater, how to set? Use this command?
ip prefix-list test_ipv4_1_1 seq 10 permit 192.18.8.0/32
---- Simon Jones _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog
participants (3)
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Daniel Corbe -
Rudy Rucker -
Simon Jones